Question

How many solutions?

y = 5(x – 4)
4x + 12 = -y

Answer 1

One solution, x = 8/9

Explanation:

One way to solve this is to take one equation and substitute into the other and then solve. So, take y=5(x-4) and put that into the other equation.

4x + 12 = -y

4x + 12 = -(5(x-4)) <--- substitution here

4x + 12 = -5(x-4)

4x + 12 = -5x + 20 <-- simplifying

4x + 5x = 20 - 12

9x = 8

x = 8/9