Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 3 + 3 + 6 + 7
p = 19

The area of a rectangle is equal to its length x width:

a = l x w
a = a x b
a = 3 x 6
a = 18

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.)

3b(b - z)
3(-6)(-6 + 5)
3(-6)(-1)
(-18)(-1)
18

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 b° = 162, the value of z° is 18.

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)(9ab) - (4a²)(6b)
(2 x 9)(a x a x b) - (4 x 6)(a² x b)
(18)(a¹⁺¹ x b) - (24)(a²b)
18a²b - 24a²b
-6a²b