Solve for b, then find the value of b when a = 3
4a = 2b - 7
CPhill : Just a slight error in obtaining b:
b = 2 a + 7/2, where a = 3
b =2*3 + 7/2
b =6 + 7/2
b=[12 + 7] / 2
b = 19/2
yea i got the same answer but if u want the answer as a whole then either the value of a is wrong or u wrote the wrong equation