Precalculus Examples

Solve by Substitution (x^2)/9+(y^2)/25=1 , y=(x-3)^2
x29+y225=1 , y=(x-3)2
Step 1
Simplify (x-3)2.
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Step 1.1
Rewrite (x-3)2 as (x-3)(x-3).
y=(x-3)(x-3)
x29+y225=1
Step 1.2
Expand (x-3)(x-3) using the FOIL Method.
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Step 1.2.1
Apply the distributive property.
y=x(x-3)-3(x-3)
x29+y225=1
Step 1.2.2
Apply the distributive property.
y=xx+x-3-3(x-3)
x29+y225=1
Step 1.2.3
Apply the distributive property.
y=xx+x-3-3x-3-3
x29+y225=1
y=xx+x-3-3x-3-3
x29+y225=1
Step 1.3
Simplify and combine like terms.
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Step 1.3.1
Simplify each term.
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Step 1.3.1.1
Multiply x by x.
y=x2+x-3-3x-3-3
x29+y225=1
Step 1.3.1.2
Move -3 to the left of x.
y=x2-3x-3x-3-3
x29+y225=1
Step 1.3.1.3
Multiply -3 by -3.
y=x2-3x-3x+9
x29+y225=1
y=x2-3x-3x+9
x29+y225=1
Step 1.3.2
Subtract 3x from -3x.
y=x2-6x+9
x29+y225=1
y=x2-6x+9
x29+y225=1
y=x2-6x+9
x29+y225=1
Step 2
Replace all occurrences of y with x2-6x+9 in each equation.
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Step 2.1
Replace all occurrences of y in x29+y225=1 with x2-6x+9.
x29+(x2-6x+9)225=1
y=x2-6x+9
Step 2.2
Simplify the left side.
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Step 2.2.1
Simplify x29+(x2-6x+9)225.
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Step 2.2.1.1
Simplify the numerator.
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Step 2.2.1.1.1
Factor using the perfect square rule.
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Step 2.2.1.1.1.1
Rewrite 9 as 32.
x29+(x2-6x+32)225=1
y=x2-6x+9
Step 2.2.1.1.1.2
Check that the middle term is two times the product of the numbers being squared in the first term and third term.
6x=2x3
Step 2.2.1.1.1.3
Rewrite the polynomial.
x29+(x2-2x3+32)225=1
y=x2-6x+9
Step 2.2.1.1.1.4
Factor using the perfect square trinomial rule a2-2ab+b2=(a-b)2, where a=x and b=3.
x29+((x-3)2)225=1
y=x2-6x+9
x29+((x-3)2)225=1
y=x2-6x+9
Step 2.2.1.1.2
Multiply the exponents in ((x-3)2)2.
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Step 2.2.1.1.2.1
Apply the power rule and multiply exponents, (am)n=amn.
x29+(x-3)2225=1
y=x2-6x+9
Step 2.2.1.1.2.2
Multiply 2 by 2.
x29+(x-3)425=1
y=x2-6x+9
x29+(x-3)425=1
y=x2-6x+9
Step 2.2.1.1.3
Use the Binomial Theorem.
x29+x4+4x3-3+6x2(-3)2+4x(-3)3+(-3)425=1
y=x2-6x+9
Step 2.2.1.1.4
Simplify each term.
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Step 2.2.1.1.4.1
Multiply -3 by 4.
x29+x4-12x3+6x2(-3)2+4x(-3)3+(-3)425=1
y=x2-6x+9
Step 2.2.1.1.4.2
Raise -3 to the power of 2.
x29+x4-12x3+6x29+4x(-3)3+(-3)425=1
y=x2-6x+9
Step 2.2.1.1.4.3
Multiply 9 by 6.
x29+x4-12x3+54x2+4x(-3)3+(-3)425=1
y=x2-6x+9
Step 2.2.1.1.4.4
Raise -3 to the power of 3.
x29+x4-12x3+54x2+4x-27+(-3)425=1
y=x2-6x+9
Step 2.2.1.1.4.5
Multiply -27 by 4.
x29+x4-12x3+54x2-108x+(-3)425=1
y=x2-6x+9
Step 2.2.1.1.4.6
Raise -3 to the power of 4.
x29+x4-12x3+54x2-108x+8125=1
y=x2-6x+9
x29+x4-12x3+54x2-108x+8125=1
y=x2-6x+9
Step 2.2.1.1.5
Make each term match the terms from the binomial theorem formula.
x29+x4-4(3x3)+6(32x2)-4(33x)+3425=1
y=x2-6x+9
Step 2.2.1.1.6
Factor x4-43x3+632x2-433x+34 using the binomial theorem.
x29+(3-x)425=1
y=x2-6x+9
x29+(3-x)425=1
y=x2-6x+9
Step 2.2.1.2
To write x29 as a fraction with a common denominator, multiply by 2525.
x292525+(3-x)425=1
y=x2-6x+9
Step 2.2.1.3
To write (3-x)425 as a fraction with a common denominator, multiply by 99.
x292525+(3-x)42599=1
y=x2-6x+9
Step 2.2.1.4
Write each expression with a common denominator of 225, by multiplying each by an appropriate factor of 1.
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Step 2.2.1.4.1
Multiply x29 by 2525.
x225925+(3-x)42599=1
y=x2-6x+9
Step 2.2.1.4.2
Multiply 9 by 25.
x225225+(3-x)42599=1
y=x2-6x+9
Step 2.2.1.4.3
Multiply (3-x)425 by 99.
x225225+(3-x)49259=1
y=x2-6x+9
Step 2.2.1.4.4
Multiply 25 by 9.
x225225+(3-x)49225=1
y=x2-6x+9
x225225+(3-x)49225=1
y=x2-6x+9
Step 2.2.1.5
Combine the numerators over the common denominator.
x225+(3-x)49225=1
y=x2-6x+9
Step 2.2.1.6
Simplify the numerator.
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Step 2.2.1.6.1
Move 25 to the left of x2.
25x2+(3-x)49225=1
y=x2-6x+9
Step 2.2.1.6.2
Use the Binomial Theorem.
25x2+(34+4(33(-x))+6(32(-x)2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3
Simplify each term.
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Step 2.2.1.6.3.1
Raise 3 to the power of 4.
25x2+(81+4(33(-x))+6(32(-x)2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.2
Raise 3 to the power of 3.
25x2+(81+4(27(-x))+6(32(-x)2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.3
Multiply 4 by 27.
25x2+(81+108(-x)+6(32(-x)2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.4
Multiply -1 by 108.
25x2+(81-108x+6(32(-x)2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.5
Raise 3 to the power of 2.
25x2+(81-108x+6(9(-x)2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.6
Multiply 6 by 9.
25x2+(81-108x+54(-x)2+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.7
Apply the product rule to -x.
25x2+(81-108x+54((-1)2x2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.8
Raise -1 to the power of 2.
25x2+(81-108x+54(1x2)+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.9
Multiply x2 by 1.
25x2+(81-108x+54x2+4(3(-x)3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.10
Multiply 4 by 3.
25x2+(81-108x+54x2+12(-x)3+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.11
Apply the product rule to -x.
25x2+(81-108x+54x2+12((-1)3x3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.12
Raise -1 to the power of 3.
25x2+(81-108x+54x2+12(-x3)+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.13
Multiply -1 by 12.
25x2+(81-108x+54x2-12x3+(-x)4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.14
Apply the product rule to -x.
25x2+(81-108x+54x2-12x3+(-1)4x4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.15
Raise -1 to the power of 4.
25x2+(81-108x+54x2-12x3+1x4)9225=1
y=x2-6x+9
Step 2.2.1.6.3.16
Multiply x4 by 1.
25x2+(81-108x+54x2-12x3+x4)9225=1
y=x2-6x+9
25x2+(81-108x+54x2-12x3+x4)9225=1
y=x2-6x+9
Step 2.2.1.6.4
Apply the distributive property.
25x2+819-108x9+54x29-12x39+x49225=1
y=x2-6x+9
Step 2.2.1.6.5
Simplify.
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Step 2.2.1.6.5.1
Multiply 81 by 9.
25x2+729-108x9+54x29-12x39+x49225=1
y=x2-6x+9
Step 2.2.1.6.5.2
Multiply 9 by -108.
25x2+729-972x+54x29-12x39+x49225=1
y=x2-6x+9
Step 2.2.1.6.5.3
Multiply 9 by 54.
25x2+729-972x+486x2-12x39+x49225=1
y=x2-6x+9
Step 2.2.1.6.5.4
Multiply 9 by -12.
25x2+729-972x+486x2-108x3+x49225=1
y=x2-6x+9
Step 2.2.1.6.5.5
Move 9 to the left of x4.
25x2+729-972x+486x2-108x3+9x4225=1
y=x2-6x+9
25x2+729-972x+486x2-108x3+9x4225=1
y=x2-6x+9
Step 2.2.1.6.6
Add 25x2 and 486x2.
511x2+729-972x-108x3+9x4225=1
y=x2-6x+9
Step 2.2.1.6.7
Reorder terms.
9x4-108x3+511x2-972x+729225=1
y=x2-6x+9
9x4-108x3+511x2-972x+729225=1
y=x2-6x+9
9x4-108x3+511x2-972x+729225=1
y=x2-6x+9
9x4-108x3+511x2-972x+729225=1
y=x2-6x+9
9x4-108x3+511x2-972x+729225=1
y=x2-6x+9
Step 3
Graph each side of the equation. The solution is the x-value of the point of intersection.
x0.80535522,3
y=x2-6x+9
Step 4
Remove any equations from the system that are always true.
x0.80535522
y=x2-6x+9
Step 5
 [x2  12  π  xdx ]