Ok it is 3b-6 over (like a fraction) 2b+3 = 9 over (like a fraction) 4 help!

Use the "cross product", the result is:

4 x (3b-6) = 9 x (2b+3)
12b - 24 = 18b + 27
-6b = 51
b = -51/6

4 x (3b-6) = 9 x (2b+3)

12b - 24 = 18b + 27
-6b = 51
b = -51/6