Question

Solve the system of equations, if there are infinitely many solutions write answers in terms of z.

x+4y-2z=-3
2x-y+5z=12
8x+5y+11z=30

x=
y=
z=

Answer 1

first multiply the first one by 5 and the second one by 2
5x+20y-10z=-15
4x-2y+10z=24
sum them
9x+18y=9
x+2y=1