Question

Use addition or substitution to find the value of y for this set of equations.
2x - 3y = -15
x = 4y

Answer 1

you could use either but substitution would be easier

Answer 2

use x=4y to substitute in the equation 2x-3y=-15
which will be: 2(4y)-3y=-15
8y-3y=-15
5y=-15
y=-3
ifyou substitute y=-3 in the original equation you will get the value of x which is -12
Good luck