Precalculus Examples

Solve by Addition/Elimination 2x^2-8y^3=19 , 4x^2+16y^3=34
2x2-8y3=192x28y3=19 , 4x2+16y3=344x2+16y3=34
Step 1
Simplify the left side.
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Step 1.1
Reorder 2x22x2 and -8y38y3.
-8y3+2x2=198y3+2x2=19
4x2+16y3=344x2+16y3=34
-8y3+2x2=198y3+2x2=19
4x2+16y3=344x2+16y3=34
Step 2
Simplify the left side.
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Step 2.1
Reorder 4x24x2 and 16y316y3.
16y3+4x2=3416y3+4x2=34
-8y3+2x2=198y3+2x2=19
16y3+4x2=3416y3+4x2=34
-8y3+2x2=198y3+2x2=19
Step 3
Multiply each equation by the value that makes the coefficients of x2x2 opposite.
-2(-8y3+2x2)=(-2)(19)2(8y3+2x2)=(2)(19)
16y3+4x2=3416y3+4x2=34
Step 4
Simplify.
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Step 4.1
Simplify the left side.
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Step 4.1.1
Simplify -2(-8y3+2x2)2(8y3+2x2).
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Step 4.1.1.1
Apply the distributive property.
-2(-8y3)-2(2x2)=(-2)(19)2(8y3)2(2x2)=(2)(19)
16y3+4x2=3416y3+4x2=34
Step 4.1.1.2
Multiply.
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Step 4.1.1.2.1
Multiply -88 by -22.
16y3-2(2x2)=(-2)(19)16y32(2x2)=(2)(19)
16y3+4x2=3416y3+4x2=34
Step 4.1.1.2.2
Multiply 22 by -22.
16y3-4x2=(-2)(19)16y34x2=(2)(19)
16y3+4x2=3416y3+4x2=34
16y3-4x2=(-2)(19)16y34x2=(2)(19)
16y3+4x2=3416y3+4x2=34
16y3-4x2=(-2)(19)16y34x2=(2)(19)
16y3+4x2=3416y3+4x2=34
16y3-4x2=(-2)(19)16y34x2=(2)(19)
16y3+4x2=3416y3+4x2=34
Step 4.2
Simplify the right side.
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Step 4.2.1
Multiply -22 by 1919.
16y3-4x2=-3816y34x2=38
16y3+4x2=3416y3+4x2=34
16y3-4x2=-3816y34x2=38
16y3+4x2=3416y3+4x2=34
16y3-4x2=-3816y34x2=38
16y3+4x2=3416y3+4x2=34
Step 5
Add the two equations together to eliminate x2x2 from the system.
1166y3y3-44x2x2==-3388
++1166y3y3++44x2x2==3344
3322y3y3==-44
Step 6
Divide each term in 32y3=-432y3=4 by 3232 and simplify.
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Step 6.1
Divide each term in 32y3=-432y3=4 by 3232.
32y332=-43232y332=432
Step 6.2
Simplify the left side.
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Step 6.2.1
Cancel the common factor of 3232.
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Step 6.2.1.1
Cancel the common factor.
32y332=-432
Step 6.2.1.2
Divide y3 by 1.
y3=-432
y3=-432
y3=-432
Step 6.3
Simplify the right side.
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Step 6.3.1
Cancel the common factor of -4 and 32.
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Step 6.3.1.1
Factor 4 out of -4.
y3=4(-1)32
Step 6.3.1.2
Cancel the common factors.
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Step 6.3.1.2.1
Factor 4 out of 32.
y3=4-148
Step 6.3.1.2.2
Cancel the common factor.
y3=4-148
Step 6.3.1.2.3
Rewrite the expression.
y3=-18
y3=-18
y3=-18
Step 6.3.2
Move the negative in front of the fraction.
y3=-18
y3=-18
y3=-18
Step 7
Substitute the value found for y3 into one of the original equations, then solve for x2.
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Step 7.1
Substitute the value found for y3 into one of the original equations to solve for x2.
16(-18)-4x2=-38
Step 7.2
Simplify each term.
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Step 7.2.1
Cancel the common factor of 8.
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Step 7.2.1.1
Move the leading negative in -18 into the numerator.
16(-18)-4x2=-38
Step 7.2.1.2
Factor 8 out of 16.
8(2)-18-4x2=-38
Step 7.2.1.3
Cancel the common factor.
82-18-4x2=-38
Step 7.2.1.4
Rewrite the expression.
2-1-4x2=-38
2-1-4x2=-38
Step 7.2.2
Multiply 2 by -1.
-2-4x2=-38
-2-4x2=-38
Step 7.3
Move all terms not containing x2 to the right side of the equation.
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Step 7.3.1
Add 2 to both sides of the equation.
-4x2=-38+2
Step 7.3.2
Add -38 and 2.
-4x2=-36
-4x2=-36
Step 7.4
Divide each term in -4x2=-36 by -4 and simplify.
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Step 7.4.1
Divide each term in -4x2=-36 by -4.
-4x2-4=-36-4
Step 7.4.2
Simplify the left side.
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Step 7.4.2.1
Cancel the common factor of -4.
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Step 7.4.2.1.1
Cancel the common factor.
-4x2-4=-36-4
Step 7.4.2.1.2
Divide x2 by 1.
x2=-36-4
x2=-36-4
x2=-36-4
Step 7.4.3
Simplify the right side.
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Step 7.4.3.1
Divide -36 by -4.
x2=9
x2=9
x2=9
x2=9
Step 8
This is the final solution to the independent system of equations.
y3=-18
x2=9
Step 9
Add 18 to both sides of the equation.
y3+18=0
x2=9
Step 10
Factor the left side of the equation.
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Step 10.1
Rewrite 1 as 13.
y3+138=0
x2=9
Step 10.2
Rewrite 8 as 23.
y3+1323=0
x2=9
Step 10.3
Rewrite 1323 as (12)3.
y3+(12)3=0
x2=9
Step 10.4
Since both terms are perfect cubes, factor using the sum of cubes formula, a3+b3=(a+b)(a2-ab+b2) where a=y and b=12.
(y+12)(y2-y12+(12)2)=0
x2=9
Step 10.5
Simplify.
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Step 10.5.1
Combine 12 and y.
(y+12)(y2-y2+(12)2)=0
x2=9
Step 10.5.2
Apply the product rule to 12.
(y+12)(y2-y2+1222)=0
x2=9
Step 10.5.3
One to any power is one.
(y+12)(y2-y2+122)=0
x2=9
Step 10.5.4
Raise 2 to the power of 2.
(y+12)(y2-y2+14)=0
x2=9
(y+12)(y2-y2+14)=0
x2=9
(y+12)(y2-y2+14)=0
x2=9
Step 11
If any individual factor on the left side of the equation is equal to 0, the entire expression will be equal to 0.
y+12=0
y2-y2+14=0
x2=9
Step 12
Set y+12 equal to 0 and solve for y.
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Step 12.1
Set y+12 equal to 0.
y+12=0
x2=9
Step 12.2
Subtract 12 from both sides of the equation.
y=-12
x2=9
y=-12
x2=9
Step 13
Set y2-y2+14 equal to 0 and solve for y.
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Step 13.1
Set y2-y2+14 equal to 0.
y2-y2+14=0
x2=9
Step 13.2
Solve y2-y2+14=0 for y.
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Step 13.2.1
Multiply through by the least common denominator 4, then simplify.
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Step 13.2.1.1
Apply the distributive property.
4y2+4(-y2)+4(14)=0
x2=9
Step 13.2.1.2
Simplify.
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Step 13.2.1.2.1
Cancel the common factor of 2.
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Step 13.2.1.2.1.1
Move the leading negative in -y2 into the numerator.
4y2+4(-y2)+4(14)=0
x2=9
Step 13.2.1.2.1.2
Factor 2 out of 4.
4y2+2(2)(-y2)+4(14)=0
x2=9
Step 13.2.1.2.1.3
Cancel the common factor.
4y2+2(2(-y2))+4(14)=0
x2=9
Step 13.2.1.2.1.4
Rewrite the expression.
4y2+2(-y)+4(14)=0
x2=9
4y2+2(-y)+4(14)=0
x2=9
Step 13.2.1.2.2
Multiply -1 by 2.
4y2-2y+4(14)=0
x2=9
Step 13.2.1.2.3
Cancel the common factor of 4.
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Step 13.2.1.2.3.1
Cancel the common factor.
4y2-2y+4(14)=0
x2=9
Step 13.2.1.2.3.2
Rewrite the expression.
4y2-2y+1=0
x2=9
4y2-2y+1=0
x2=9
4y2-2y+1=0
x2=9
4y2-2y+1=0
x2=9
Step 13.2.2
Use the quadratic formula to find the solutions.
-b±b2-4(ac)2a
x2=9
Step 13.2.3
Substitute the values a=4, b=-2, and c=1 into the quadratic formula and solve for y.
2±(-2)2-4(41)24
x2=9
Step 13.2.4
Simplify.
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Step 13.2.4.1
Simplify the numerator.
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Step 13.2.4.1.1
Raise -2 to the power of 2.
y=2±4-44124
x2=9
Step 13.2.4.1.2
Multiply -441.
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Step 13.2.4.1.2.1
Multiply -4 by 4.
y=2±4-16124
x2=9
Step 13.2.4.1.2.2
Multiply -16 by 1.
y=2±4-1624
x2=9
y=2±4-1624
x2=9
Step 13.2.4.1.3
Subtract 16 from 4.
y=2±-1224
x2=9
Step 13.2.4.1.4
Rewrite -12 as -1(12).
y=2±-11224
x2=9
Step 13.2.4.1.5
Rewrite -1(12) as -112.
y=2±-11224
x2=9
Step 13.2.4.1.6
Rewrite -1 as i.
y=2±i1224
x2=9
Step 13.2.4.1.7
Rewrite 12 as 223.
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Step 13.2.4.1.7.1
Factor 4 out of 12.
y=2±i4(3)24
x2=9
Step 13.2.4.1.7.2
Rewrite 4 as 22.
y=2±i22324
x2=9
y=2±i22324
x2=9
Step 13.2.4.1.8
Pull terms out from under the radical.
y=2±i(23)24
x2=9
Step 13.2.4.1.9
Move 2 to the left of i.
y=2±2i324
x2=9
y=2±2i324
x2=9
Step 13.2.4.2
Multiply 2 by 4.
y=2±2i38
x2=9
Step 13.2.4.3
Simplify 2±2i38.
y=1±i34
x2=9
y=1±i34
x2=9
Step 13.2.5
Simplify the expression to solve for the + portion of the ±.
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Step 13.2.5.1
Simplify the numerator.
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Step 13.2.5.1.1
Raise -2 to the power of 2.
y=2±4-44124
x2=9
Step 13.2.5.1.2
Multiply -441.
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Step 13.2.5.1.2.1
Multiply -4 by 4.
y=2±4-16124
x2=9
Step 13.2.5.1.2.2
Multiply -16 by 1.
y=2±4-1624
x2=9
y=2±4-1624
x2=9
Step 13.2.5.1.3
Subtract 16 from 4.
y=2±-1224
x2=9
Step 13.2.5.1.4
Rewrite -12 as -1(12).
y=2±-11224
x2=9
Step 13.2.5.1.5
Rewrite -1(12) as -112.
y=2±-11224
x2=9
Step 13.2.5.1.6
Rewrite -1 as i.
y=2±i1224
x2=9
Step 13.2.5.1.7
Rewrite 12 as 223.
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Step 13.2.5.1.7.1
Factor 4 out of 12.
y=2±i4(3)24
x2=9
Step 13.2.5.1.7.2
Rewrite 4 as 22.
y=2±i22324
x2=9
y=2±i22324
x2=9
Step 13.2.5.1.8
Pull terms out from under the radical.
y=2±i(23)24
x2=9
Step 13.2.5.1.9
Move 2 to the left of i.
y=2±2i324
x2=9
y=2±2i324
x2=9
Step 13.2.5.2
Multiply 2 by 4.
y=2±2i38
x2=9
Step 13.2.5.3
Simplify 2±2i38.
y=1±i34
x2=9
Step 13.2.5.4
Change the ± to +.
y=1+i34
x2=9
y=1+i34
x2=9
Step 13.2.6
Simplify the expression to solve for the - portion of the ±.
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Step 13.2.6.1
Simplify the numerator.
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Step 13.2.6.1.1
Raise -2 to the power of 2.
y=2±4-44124
x2=9
Step 13.2.6.1.2
Multiply -441.
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Step 13.2.6.1.2.1
Multiply -4 by 4.
y=2±4-16124
x2=9
Step 13.2.6.1.2.2
Multiply -16 by 1.
y=2±4-1624
x2=9
y=2±4-1624
x2=9
Step 13.2.6.1.3
Subtract 16 from 4.
y=2±-1224
x2=9
Step 13.2.6.1.4
Rewrite -12 as -1(12).
y=2±-11224
x2=9
Step 13.2.6.1.5
Rewrite -1(12) as -112.
y=2±-11224
x2=9
Step 13.2.6.1.6
Rewrite -1 as i.
y=2±i1224
x2=9
Step 13.2.6.1.7
Rewrite 12 as 223.
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Step 13.2.6.1.7.1
Factor 4 out of 12.
y=2±i4(3)24
x2=9
Step 13.2.6.1.7.2
Rewrite 4 as 22.
y=2±i22324
x2=9
y=2±i22324
x2=9
Step 13.2.6.1.8
Pull terms out from under the radical.
y=2±i(23)24
x2=9
Step 13.2.6.1.9
Move 2 to the left of i.
y=2±2i324
x2=9
y=2±2i324
x2=9
Step 13.2.6.2
Multiply 2 by 4.
y=2±2i38
x2=9
Step 13.2.6.3
Simplify 2±2i38.
y=1±i34
x2=9
Step 13.2.6.4
Change the ± to -.
y=1-i34
x2=9
y=1-i34
x2=9
Step 13.2.7
The final answer is the combination of both solutions.
y=1+i34,1-i34
x2=9
y=1+i34,1-i34
x2=9
y=1+i34,1-i34
x2=9
Step 14
The final solution is all the values that make (y+12)(y2-y2+14)=0 true.
y=-12,1+i34,1-i34
x2=9
Step 15
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
x=±9
y=-12,1+i34,1-i34
Step 16
Simplify ±9.
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Step 16.1
Rewrite 9 as 32.
x=±32
y=-12,1+i34,1-i34
Step 16.2
Pull terms out from under the radical, assuming positive real numbers.
x=±3
y=-12,1+i34,1-i34
x=±3
y=-12,1+i34,1-i34
Step 17
The complete solution is the result of both the positive and negative portions of the solution.
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Step 17.1
First, use the positive value of the ± to find the first solution.
x=3
y=-12,1+i34,1-i34
Step 17.2
Next, use the negative value of the ± to find the second solution.
x=-3
y=-12,1+i34,1-i34
Step 17.3
The complete solution is the result of both the positive and negative portions of the solution.
x=3,-3
y=-12,1+i34,1-i34
x=3,-3
y=-12,1+i34,1-i34
Step 18
The final result is the combination of all values of x with all values of y.
(3,-12),(3,1+i34),(3,1-i34),(-3,-12),(-3,1+i34),(-3,1-i34)
Step 19
 [x2  12  π  xdx ]