how do i solve this using substitution?

Question

5x+y=15
4x+4y=12

Answer 1

y = 15-5x

replace y into the other eq

4x+4(15-5x) = 12

4x + 60 - 20x = 12
-16x = -48

x = 3

plug 3 onto the fisrt or second eq to get Y..

y = 15-5x
y = 15-5(3)

y = 0