What is the first step to solving this system of equations using the substitution method?

Question

z + y = 11
x = - y - 9

substitute y=11 in for x in the bottom equation

substitute -y-9 in for x in the top equation

add the equations together

No answer text provided.

Answer 1

The first step to solving this system of equations using the substitution method is to substitute the expression for x from one of the equations into the other equation. In this case, you would substitute -y - 9 for x in the first equation.