To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.

To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses.

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

3a⁴ - 5a⁴ = -2a⁴

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(3a)(5ab) - (2a²)(8b)
(3 x 5)(a x a x b) - (2 x 8)(a² x b)
(15)(a¹⁺¹ x b) - (16)(a²b)
15a²b - 16a²b
-1a²b

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.

9a - 5 = \( \frac{a}{1} \)
1 x (9a - 5) = a
(1 x 9a) + (1 x -5) = a
9a - 5 = a
9a - 5 - a = 0
9a - a = 5
8a = 5
a = \( \frac{5}{8} \)
a = \(\frac{5}{8}\)