Answer:
B. 0.90x=43
E.2(x-0.10x+2.5)=91
Step-by-step explanation:
Given equation:
  x-0.10x+2.5 = 45.5
   Let us simplify this;
Collect like terms;
     x - 0.10x = 45.5 - 2.5
Simplify;
       0.9x = 43 (Option A)
Also;
    x-0.10x+2.5 = 45.5
   Simplify by multiplying both sides by 2;
  2(x - 0.10x + 2.5) = 2(45.5)
  2(x - 0.10x + 2.5) = 91.0
Also;
   x-0.10x+2.5 = 45.5
    0.9x + 2.5 = 45.5
Those are the three scenarios