Q. Solve the system of equations by elimination.2x−y−z=−4−2x−3y−2z=−162x+y−2z=16
Eliminate x by adding equations: Add the first and second equations to eliminate x.(2x−y−z)+(−2x−3y−2z)=−4+(−16)2x−y−z−2x−3y−2z=−20−4y−3z=−20
Eliminate x by adding equations: Add the first and third equations to eliminate x. (2x−y−z)+(2x+y−2z)=−4+16 2x−y−z+2x+y−2z=12 4x−3z=12
Solve for x: Divide the last equation by 4 to solve for x. 4x−3z=12x−(43)z=3x=3+(43)z
Substitute x into first equation: Substitute x=3+43z into the first equation.2(3+43z)−y−z=−46+23z−y−z=−46+21z−y=−4
Isolate terms with variables: Subtract 6 from both sides to isolate the terms with variables.6+(21)z−y−6=−4−6(21)z−y=−10
Get rid of fraction: Multiply the equation by 2 to get rid of the fraction.2(21z−y)=2(−10)z−2y=−20
Align y terms: Now we have a system with two equations and two variables:−4y−3z=−20z−2y=−20Multiply the second equation by 2 to align the y terms.2(z−2y)=2(−20)2z−4y=−40
Eliminate y: Add the modified second equation to the first equation to eliminate y.(−4y−3z)+(2z−4y)=−20+(−40)−8y−z=−60
Solve for y: Divide the equation by −8 to solve for y.−8y−z=−60y+81z=7.5y=7.5−81z
Substitute y into equation: Substitute y=7.5−81z into the equation z−2y=−20.z−2(7.5−81z)=−20z−15+41z=−2045z=−5z=45−5z=−4
Find z: Substitute z=−4 into y=7.5−81z to find y.y=7.5−81(−4)y=7.5+0.5y=8
Find y: Substitute z=−4 into x=3+(43)z to find x.x=3+(43)(−4)x=3−3x=0
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