Question

50% of A is equal to $120 and 120% of B is equal to $90

Answer 1

50% = 0.5
50% of A = $120
A x 50% = $120
A x 0.5 = $120
0.5A = $120
0.5A/0.5 = $120/0.5
A = $240
.
120% = 1.2
120% of B = $90
B x 120% = $90
B x 1.2 = $90
1.2B = $90
1.2B/1.2 = $90/1.2
B = $75
.
.
:)

Answer 2

What do u want to know?
A x 50% = $ 120
B x 120% = $ 90