If a = -3n + 2, and b = 5n - 7, what is the value of a + b, in simplest form

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

41/17 as a decimal rounded to the nearest hundredth

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x