Question

How can I resolve 5-3*= -45??
(* means X)

Answer 1

5-3x = -45
you subtract 5 from both sides and get:
-3x = -50 
then you divide by -3 on both sides and get:
x = 16.66666666667

Answer 2

  5 - 3x = -45
-5             -5
     -3x = -50
       -3      -3
       x  ≈ 16.67