Stephanie is x years old. Tobi is twice as old as Stephanie. Ulrika is 3 years younger than Tobi. The sum of all their ages is 52 years. Work out the value of x.

Can someone explain to me how to do

Erinn wrote the equation –5x + 4y = 32 to represent her hourly wage (y) and how this wage has changed during each year that she worked at a company (x). what is the rate of change in erinn's hourly wage per year?

Express -5 2/5 as an improper fraction.