Question

Solve the system by elimination (What is the value of X, Y, & Z)
-2x+y-2z=-10
-2x+y-z=-10
-x-y-3z=1

Answer 1

solve the third quation for x
x=-y-3z-1
then put the value of x on the othere equations
-2(-y-3z-1)+y-2z=-10
2y+6z+2+y-2z=-10
3y+4z=-12
the second equation
-2(-y-3z-1)+y-z=-10
2y+6z+2+y-z=-10
3y+5z=-12
now sloving 3y+5z=-12 for y
3y=(-12-5z)
putting this value for y in the othere equation..
3y+4z=-12

-12-5z+4z=-12
-z=-12+12=0
solving for 3y+4z=-12...... 3y+4(0)=-12.... y=-12/3=-4
soving for x
-2x+y-z=-10
x=(-10+4)/-2=-6/-2=3