If 6 less than the product of 9 and a number is equal to 48, what is the number?

If x y = (5x - 4y)/y , find the value of y if 6 y = 2.

Simplify the expression:

Given , simplify the following expression.

Evaluate: (2x + 4)(x2 – 2x + 4)

Which of the following does not simplify to ?

Simplify the following expression: x3 - 4(x2 + 3) + 15

Let f(x) be a function, and let a and b represent any numbers belonging to the domain of f(x). If f(a + b) = f(a) + f(b) for all of the possible values of a and b, then f(x) is considered "special." Which of the following functions is special?

Solve for x: 2y/3b = 5x/7a

If ab = –8, and _a_2 + _b_2 = 20, then what is (a – b)2?