q 1 solving systems of equations by substitution, can you help me?

Question

y=7/4x-3

y=4 (please ignore this part, i needed 30 characters, and my question only had 11)

Answer 1

Just substitute 4 for y in the first equation and you get

4=7/4x-3

4(4x-3) =7

16x -12 =7

16x=19

x=19/16