Question

150% of A is equal to $120

Answer 1

We can make this into an equation like so:

150/100A=120

Simplify

3/2A=120

A=80

Answer 2

So, your question is kind of vague (if not even a question), but I'll guess on what you want...

So, to find 150% of A, we use this equation:
1.5a = 120
We divide both sides by 1.5 to isolate a:
a = 80
150% of 80 is equal to 120