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.

2x + 5y – 2z = –1
x + 3y + z = –2
3x – 2y + 3z = –17

–y – 4z = 3
–11y = –11

11y = 3
7y + 6z = –11

4x + 11y = –5
–11y = –11

–y = –5
6x + 7y = –11

Answer 1

The second equation: x + 3y + z= -2
x=-3y -x - 2 x is now isolated

Answer 2

We now substitute for x in the first and third equation and see what you get.

Answer 3

its the 2nd one?

Answer 4

Let me check. 2(-3y-z-2) + 5y-2z=-1 note typo in y first post change -x to -z in isolations of x.
-6y-2z-4 + 5y-2z=-1
-y-4z=3 yes the second one as the remaining does not have that so no need to verify the third equation.

Answer 5

thanks so much

Answer 6

No problem for my own edification I will also do the third one to verify.
3(-3y-z-2)-2y+3z=-17
-9y-3z-6-2y+3z=-17
-11y=-11 Yep.

Answer 7

can you help me with the other one i just posted