Algebra 2 Word Problem: Any help would be much appreciated

Question

SKYSCRAPERS While working on a high-rise building, a window washer is trying to mix a diluted cleaning solution that is 55% soap. He is adding an 80% soap solution to 1 liter of 40% soap solution. How much does he need to add, in order to get the proper soap solution?

Answer 1

0.8X + 1 * 0.4 = (X+1)*0.55

0.8X + 0.4 = 0.55X + 0.55

0.25X = 0.15

25x = 15

x = 15/25 = 3/5 = 0.6

0.6 = 3/5 liter of the 80% soap solution

Answer 2

If x is the amount of solution to be added (in liters), then the final amount of solution is x+1, and we have:

0.8x + .0.4(1) = 0.55(x+1)

Solving for x:

0.8x + 0.4 = 0.55x + 0.55

0.25x = 0.15

x = 0.60

Thus, 0.60 liters of solution must be added.