Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 8 + 9 + 6 + 9
p = 32

Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and 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°).

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.

(8a)(8ab) + (6a²)(4b)
(8 x 8)(a x a x b) + (6 x 4)(a² x b)
(64)(a¹⁺¹ x b) + (24)(a²b)
64a²b + 24a²b
88a²b

When solving an equation with two variables, 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.)

To solve this equation, isolate the variable for which you are solving (b) on one side of the equation and put everything else on the other side.

-b + 7z = -3b - 9z + 2
-b = -3b - 9z + 2 - 7z
-b + 3b = -9z + 2 - 7z
2b = -16z + 2
b = \( \frac{-16z + 2}{2} \)
b = \( \frac{-16z}{2} \) + \( \frac{2}{2} \)
b = -8z + 1