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 + 9)(y + 4)
(y x y) + (y x 4) + (9 x y) + (9 x 4)
y² + 4y + 9y + 36
y² + 13y + 36

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.

(9a)(8ab) + (5a²)(5b)
(9 x 8)(a x a x b) + (5 x 5)(a² x b)
(72)(a¹⁺¹ x b) + (25)(a²b)
72a²b + 25a²b
97a²b

The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):

sa = 2lw + 2wh + 2lh
sa = (2 x 5 x 3) + (2 x 3 x 4) + (2 x 5 x 4)
sa = (30) + (24) + (40)
sa = 94

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 < sign and the answer on the other.

6y - 9 < \( \frac{y}{2} \)
2 x (6y - 9) < y
(2 x 6y) + (2 x -9) < y
12y - 18 < y
12y - 18 - y < 0
12y - y < 18
11y < 18
y < \( \frac{18}{11} \)
y < 1\(\frac{7}{11}\)

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.