does anyone know how to do this

Answer:
y = 1
Step-by-step explanation:
4 - (y-3) = 3(y+1) - 4(1 - y)
4 -y +3 = 3y + 3 - 4 + 4y
7 - y = 7y - 1
7 + 1 = 7y + y
8 = 8y
8/8 = y