solve

Hi!

3a + 4b = 5a - 6b + 24 - 3a 

First let's simplify : 

3a + 6b + 4b = 5a -3a + 24 

= 3a + 10 b = 2a + 24 

Now let us move everything that isn't A onto 1 side : 

3a - 2a  = 24 + (-10 b)

a = (-10) b + 24 

That would be your answer