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.

6a² + 6a² = 12a²

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 - 6a⁴ = -3a⁴

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.

5a + 3a = 8a

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:

(y - 2)(y - 5)
(y x y) + (y x -5) + (-2 x y) + (-2 x -5)
y² - 5y - 2y + 10
y² - 7y + 10

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.

(7a)(9ab) + (6a²)(3b)
(7 x 9)(a x a x b) + (6 x 3)(a² x b)
(63)(a¹⁺¹ x b) + (18)(a²b)
63a²b + 18a²b
81a²b