Question

if you were to use the substitution method to solve the following system, choose the new system of equations that would result if x was isolated in the second equation.
3x - 5y + z = 12
x + 6y - z = -4
2x - 5y - 2z = -8
possible answers:
4x + y = 8
-17y = 0

2x - 11y = 16
4x + 7y = -16

-23y + 4z = 24
-17y = 0

13y - 2z = 24
7y - 4z = 0

Answer 1

so could u isolate x from 2nd equation?

Answer 2

x= -6y + z -4

Answer 3

correct!
now put that x in 1st equation

Answer 4

3(-6y + z - 4) - 5y + z =12

Answer 5

simplify it....combine like terms

Answer 6

-18y+3z-12-5y+z=12
-23y+4z=24
got this ?

Answer 7

yes

Answer 8

I think I figured it out!

Answer 9

great! :D