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 - 2)
(y x y) + (y x -2) + (-9 x y) + (-9 x -2)
y² - 2y - 9y + 18
y² - 11y + 18

The volume of a cylinder is πr²h:

v = πr²h
v = π(6² x 1)
v = 36π

To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)

-7a(a - z)
-7(-6)(-6 - 4)
-7(-6)(-10)
(42)(-10)
-420

For parallel lines with a transversal, the following relationships apply:

• angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°)
• alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°)
• all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other
• same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°)

Applying these relationships starting with d° = 165, the value of a° is 15.

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.

(2a)(8ab) - (2a²)(7b)
(2 x 8)(a x a x b) - (2 x 7)(a² x b)
(16)(a¹⁺¹ x b) - (14)(a²b)
16a²b - 14a²b
2a²b