Algebra Examples
4x+y-2z=04x+y−2z=0 , 2x-3y+3z=92x−3y+3z=9 , -6x-2y+z=0−6x−2y+z=0
Step 1
Choose two equations and eliminate one variable. In this case, eliminate yy.
4x+y-2z=04x+y−2z=0
2x-3y+3z=92x−3y+3z=9
Step 2
Step 2.1
Multiply each equation by the value that makes the coefficients of yy opposite.
(3)⋅(4x+y-2z)=(3)(0)(3)⋅(4x+y−2z)=(3)(0)
2x-3y+3z=92x−3y+3z=9
Step 2.2
Simplify.
Step 2.2.1
Simplify the left side.
Step 2.2.1.1
Simplify (3)⋅(4x+y-2z)(3)⋅(4x+y−2z).
Step 2.2.1.1.1
Apply the distributive property.
3(4x)+3y+3(-2z)=(3)(0)3(4x)+3y+3(−2z)=(3)(0)
2x-3y+3z=92x−3y+3z=9
Step 2.2.1.1.2
Simplify.
Step 2.2.1.1.2.1
Multiply 44 by 33.
12x+3y+3(-2z)=(3)(0)12x+3y+3(−2z)=(3)(0)
2x-3y+3z=92x−3y+3z=9
Step 2.2.1.1.2.2
Multiply -2−2 by 33.
12x+3y-6z=(3)(0)12x+3y−6z=(3)(0)
2x-3y+3z=92x−3y+3z=9
12x+3y-6z=(3)(0)12x+3y−6z=(3)(0)
2x-3y+3z=92x−3y+3z=9
12x+3y-6z=(3)(0)12x+3y−6z=(3)(0)
2x-3y+3z=92x−3y+3z=9
12x+3y-6z=(3)(0)12x+3y−6z=(3)(0)
2x-3y+3z=92x−3y+3z=9
Step 2.2.2
Simplify the right side.
Step 2.2.2.1
Multiply 33 by 00.
12x+3y-6z=012x+3y−6z=0
2x-3y+3z=92x−3y+3z=9
12x+3y-6z=012x+3y−6z=0
2x-3y+3z=92x−3y+3z=9
12x+3y-6z=012x+3y−6z=0
2x-3y+3z=92x−3y+3z=9
Step 2.3
Add the two equations together to eliminate yy from the system.
11 | 22 | xx | ++ | 33 | yy | -− | 66 | zz | == | 00 | |||
++ | 22 | xx | -− | 33 | yy | ++ | 33 | zz | == | 99 | |||
11 | 44 | xx | -− | 33 | zz | == | 99 |
Step 2.4
The resultant equation has yy eliminated.
14x-3z=914x−3z=9
14x-3z=914x−3z=9
Step 3
Choose another two equations and eliminate yy.
2x-3y+3z=92x−3y+3z=9
-6x-2y+z=0−6x−2y+z=0
Step 4
Step 4.1
Multiply each equation by the value that makes the coefficients of yy opposite.
(-2)⋅(2x-3y+3z)=(-2)(9)(−2)⋅(2x−3y+3z)=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
Step 4.2
Simplify.
Step 4.2.1
Simplify the left side.
Step 4.2.1.1
Simplify (-2)⋅(2x-3y+3z)(−2)⋅(2x−3y+3z).
Step 4.2.1.1.1
Apply the distributive property.
-2(2x)-2(-3y)-2(3z)=(-2)(9)−2(2x)−2(−3y)−2(3z)=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
Step 4.2.1.1.2
Simplify.
Step 4.2.1.1.2.1
Multiply 22 by -2−2.
-4x-2(-3y)-2(3z)=(-2)(9)−4x−2(−3y)−2(3z)=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
Step 4.2.1.1.2.2
Multiply -3−3 by -2−2.
-4x+6y-2(3z)=(-2)(9)−4x+6y−2(3z)=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
Step 4.2.1.1.2.3
Multiply 33 by -2−2.
-4x+6y-6z=(-2)(9)−4x+6y−6z=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
-4x+6y-6z=(-2)(9)−4x+6y−6z=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
-4x+6y-6z=(-2)(9)−4x+6y−6z=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
-4x+6y-6z=(-2)(9)−4x+6y−6z=(−2)(9)
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
Step 4.2.2
Simplify the right side.
Step 4.2.2.1
Multiply -2−2 by 99.
-4x+6y-6z=-18−4x+6y−6z=−18
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
-4x+6y-6z=-18−4x+6y−6z=−18
(3)⋅(-6x-2y+z)=(3)(0)(3)⋅(−6x−2y+z)=(3)(0)
Step 4.2.3
Simplify the left side.
Step 4.2.3.1
Simplify (3)⋅(-6x-2y+z)(3)⋅(−6x−2y+z).
Step 4.2.3.1.1
Apply the distributive property.
-4x+6y-6z=-18−4x+6y−6z=−18
3(-6x)+3(-2y)+3z=(3)(0)3(−6x)+3(−2y)+3z=(3)(0)
Step 4.2.3.1.2
Simplify.
Step 4.2.3.1.2.1
Multiply -6−6 by 33.
-4x+6y-6z=-18−4x+6y−6z=−18
-18x+3(-2y)+3z=(3)(0)−18x+3(−2y)+3z=(3)(0)
Step 4.2.3.1.2.2
Multiply -2−2 by 33.
-4x+6y-6z=-18−4x+6y−6z=−18
-18x-6y+3z=(3)(0)−18x−6y+3z=(3)(0)
-4x+6y-6z=-18−4x+6y−6z=−18
-18x-6y+3z=(3)(0)−18x−6y+3z=(3)(0)
-4x+6y-6z=-18−4x+6y−6z=−18
-18x-6y+3z=(3)(0)−18x−6y+3z=(3)(0)
-4x+6y-6z=-18−4x+6y−6z=−18
-18x-6y+3z=(3)(0)−18x−6y+3z=(3)(0)
Step 4.2.4
Simplify the right side.
Step 4.2.4.1
Multiply 33 by 00.
-4x+6y-6z=-18−4x+6y−6z=−18
-18x-6y+3z=0−18x−6y+3z=0
-4x+6y-6z=-18−4x+6y−6z=−18
-18x-6y+3z=0−18x−6y+3z=0
-4x+6y-6z=-18−4x+6y−6z=−18
-18x-6y+3z=0−18x−6y+3z=0
Step 4.3
Add the two equations together to eliminate yy from the system.
-− | 44 | xx | ++ | 66 | yy | -− | 66 | zz | == | -− | 11 | 88 | ||||
++ | -− | 11 | 88 | xx | -− | 66 | yy | ++ | 33 | zz | == | 00 | ||||
-− | 22 | 22 | xx | -− | 33 | zz | == | -− | 11 | 88 |
Step 4.4
The resultant equation has yy eliminated.
-22x-3z=-18−22x−3z=−18
-22x-3z=-18−22x−3z=−18
Step 5
Take the resultant equations and eliminate another variable. In this case, eliminate zz.
14x-3z=914x−3z=9
-22x-3z=-18−22x−3z=−18
Step 6
Step 6.1
Multiply each equation by the value that makes the coefficients of zz opposite.
(-1)⋅(14x-3z)=(-1)(9)(−1)⋅(14x−3z)=(−1)(9)
-22x-3z=-18−22x−3z=−18
Step 6.2
Simplify.
Step 6.2.1
Simplify the left side.
Step 6.2.1.1
Simplify (-1)⋅(14x-3z)(−1)⋅(14x−3z).
Step 6.2.1.1.1
Apply the distributive property.
-1(14x)-1(-3z)=(-1)(9)−1(14x)−1(−3z)=(−1)(9)
-22x-3z=-18−22x−3z=−18
Step 6.2.1.1.2
Multiply.
Step 6.2.1.1.2.1
Multiply 1414 by -1−1.
-14x-1(-3z)=(-1)(9)−14x−1(−3z)=(−1)(9)
-22x-3z=-18−22x−3z=−18
Step 6.2.1.1.2.2
Multiply -3−3 by -1−1.
-14x+3z=(-1)(9)−14x+3z=(−1)(9)
-22x-3z=-18−22x−3z=−18
-14x+3z=(-1)(9)−14x+3z=(−1)(9)
-22x-3z=-18−22x−3z=−18
-14x+3z=(-1)(9)−14x+3z=(−1)(9)
-22x-3z=-18−22x−3z=−18
-14x+3z=(-1)(9)−14x+3z=(−1)(9)
-22x-3z=-18−22x−3z=−18
Step 6.2.2
Simplify the right side.
Step 6.2.2.1
Multiply -1−1 by 99.
-14x+3z=-9−14x+3z=−9
-22x-3z=-18−22x−3z=−18
-14x+3z=-9−14x+3z=−9
-22x-3z=-18−22x−3z=−18
-14x+3z=-9−14x+3z=−9
-22x-3z=-18−22x−3z=−18
Step 6.3
Add the two equations together to eliminate zz from the system.
-− | 11 | 44 | xx | ++ | 33 | zz | == | -− | 99 | ||||
++ | -− | 22 | 22 | xx | -− | 33 | zz | == | -− | 11 | 88 | ||
-− | 33 | 66 | xx | == | -− | 22 | 77 |
Step 6.4
The resultant equation has zz eliminated.
-36x=-27−36x=−27
Step 6.5
Divide each term in -36x=-27−36x=−27 by -36−36 and simplify.
Step 6.5.1
Divide each term in -36x=-27−36x=−27 by -36−36.
-36x-36=-27-36−36x−36=−27−36
Step 6.5.2
Simplify the left side.
Step 6.5.2.1
Cancel the common factor of -36−36.
Step 6.5.2.1.1
Cancel the common factor.
-36x-36=-27-36
Step 6.5.2.1.2
Divide x by 1.
x=-27-36
x=-27-36
x=-27-36
Step 6.5.3
Simplify the right side.
Step 6.5.3.1
Cancel the common factor of -27 and -36.
Step 6.5.3.1.1
Factor -9 out of -27.
x=-9(3)-36
Step 6.5.3.1.2
Cancel the common factors.
Step 6.5.3.1.2.1
Factor -9 out of -36.
x=-9⋅3-9⋅4
Step 6.5.3.1.2.2
Cancel the common factor.
x=-9⋅3-9⋅4
Step 6.5.3.1.2.3
Rewrite the expression.
x=34
x=34
x=34
x=34
x=34
x=34
Step 7
Step 7.1
Substitute the value of x into an equation with y eliminated already.
14(34)-3z=9
Step 7.2
Solve for z.
Step 7.2.1
Simplify each term.
Step 7.2.1.1
Cancel the common factor of 2.
Step 7.2.1.1.1
Factor 2 out of 14.
2(7)34-3z=9
Step 7.2.1.1.2
Factor 2 out of 4.
2⋅732⋅2-3z=9
Step 7.2.1.1.3
Cancel the common factor.
2⋅732⋅2-3z=9
Step 7.2.1.1.4
Rewrite the expression.
7(32)-3z=9
7(32)-3z=9
Step 7.2.1.2
Combine 7 and 32.
7⋅32-3z=9
Step 7.2.1.3
Multiply 7 by 3.
212-3z=9
212-3z=9
Step 7.2.2
Move all terms not containing z to the right side of the equation.
Step 7.2.2.1
Subtract 212 from both sides of the equation.
-3z=9-212
Step 7.2.2.2
To write 9 as a fraction with a common denominator, multiply by 22.
-3z=9⋅22-212
Step 7.2.2.3
Combine 9 and 22.
-3z=9⋅22-212
Step 7.2.2.4
Combine the numerators over the common denominator.
-3z=9⋅2-212
Step 7.2.2.5
Simplify the numerator.
Step 7.2.2.5.1
Multiply 9 by 2.
-3z=18-212
Step 7.2.2.5.2
Subtract 21 from 18.
-3z=-32
-3z=-32
Step 7.2.2.6
Move the negative in front of the fraction.
-3z=-32
-3z=-32
Step 7.2.3
Divide each term in -3z=-32 by -3 and simplify.
Step 7.2.3.1
Divide each term in -3z=-32 by -3.
-3z-3=-32-3
Step 7.2.3.2
Simplify the left side.
Step 7.2.3.2.1
Cancel the common factor of -3.
Step 7.2.3.2.1.1
Cancel the common factor.
-3z-3=-32-3
Step 7.2.3.2.1.2
Divide z by 1.
z=-32-3
z=-32-3
z=-32-3
Step 7.2.3.3
Simplify the right side.
Step 7.2.3.3.1
Multiply the numerator by the reciprocal of the denominator.
z=-32⋅1-3
Step 7.2.3.3.2
Cancel the common factor of 3.
Step 7.2.3.3.2.1
Move the leading negative in -32 into the numerator.
z=-32⋅1-3
Step 7.2.3.3.2.2
Factor 3 out of -3.
z=3(-1)2⋅1-3
Step 7.2.3.3.2.3
Factor 3 out of -3.
z=3⋅-12⋅13⋅-1
Step 7.2.3.3.2.4
Cancel the common factor.
z=3⋅-12⋅13⋅-1
Step 7.2.3.3.2.5
Rewrite the expression.
z=-12⋅1-1
z=-12⋅1-1
Step 7.2.3.3.3
Multiply -12 by 1-1.
z=-12⋅-1
Step 7.2.3.3.4
Multiply 2 by -1.
z=-1-2
Step 7.2.3.3.5
Dividing two negative values results in a positive value.
z=12
z=12
z=12
z=12
z=12
Step 8
Step 8.1
Substitute the value of each known variable into one of the initial equations.
4(34)+y-2(12)=0
Step 8.2
Solve for y.
Step 8.2.1
Simplify 4(34)+y-2(12).
Step 8.2.1.1
Simplify each term.
Step 8.2.1.1.1
Cancel the common factor of 4.
Step 8.2.1.1.1.1
Cancel the common factor.
4(34)+y-2(12)=0
Step 8.2.1.1.1.2
Rewrite the expression.
3+y-2(12)=0
3+y-2(12)=0
Step 8.2.1.1.2
Cancel the common factor of 2.
Step 8.2.1.1.2.1
Factor 2 out of -2.
3+y+2(-1)12=0
Step 8.2.1.1.2.2
Cancel the common factor.
3+y+2⋅-112=0
Step 8.2.1.1.2.3
Rewrite the expression.
3+y-1=0
3+y-1=0
3+y-1=0
Step 8.2.1.2
Subtract 1 from 3.
y+2=0
y+2=0
Step 8.2.2
Subtract 2 from both sides of the equation.
y=-2
y=-2
y=-2
Step 9
The solution to the system of equations can be represented as a point.
(34,-2,12)
Step 10
The result can be shown in multiple forms.
Point Form:
(34,-2,12)
Equation Form:
x=34,y=-2,z=12