Solve the following system of equations, 3x +5y+2-0

Factor a^3 - 3 + 3a^2 - a. a) (a - 1)(a + 1)(a + 3) b) (a^2 + 1)(a - 3) c) (a^2 - 3)(a + 1

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid in order to get a 40% solution of acid?

Tanyss's house has 25 windows. her brother has washed 22 of the windows. what percent of the windows has her brother washed?