Please help How much water should be added to 1 gallon of pure antifreeze to obtain a solution that is 55% antifreeze?

Assume that x gallon water is added: 35% antifreeze

= 1 / (x + 1) = 0.35

1 = 0.35 x + 0.35

0.65 = 0.35(x)

x = 1.857 gallons

The answer is 1.89 gallons of waters should be added to 1 pure antifreeze to obtain a solution that is 35% antifreeze.