Question

The following system is solved by substitution. Which expression is substituted for z in the second and third equations?

x + 5y – z = 6
3x – y – 2z = 4
3x – 2y + 3z = 13
Answer
x + 5y + 6
–x – 5y + 6
x + 5y – 6
–x – 5y – 6

Answer 1

if ur gonna substitute the z into the 2nd and third equation u want to solve for z in the first equation and whatever z equals is what u substitue:
x+5y-z=6
x+5y-z+z=6+z
x+5y=6+z
x+5y-6=z+6-6
z=x+5y-6
so u would substitute
x+5y-6 into the other equations

Answer 2

for z

Answer 3

x+5y-6 is ur answer to be clear btw