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

a = l x w
a = a x b
a = 6 x 5
a = 30

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) + (8a²)(9b)
(2 x 8)(a x a x b) + (8 x 9)(a² x b)
(16)(a¹⁺¹ x b) + (72)(a²b)
16a²b + 72a²b
88a²b

A rectangle is a parallelogram containing four right angles. Opposite sides (a = c, b = d) are equal and the perimeter is the sum of the lengths of all sides (a + b + c + d) or, comonly, 2 x length x width. The area of a rectangle is length x width. A square is a rectangle with four equal length sides. The perimeter of a square is 4 x length of one side (4s) and the area is the length of one side squared (s²).

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.)

4b(b - y)
4(7)(7 + 4)
4(7)(11)
(28)(11)
308

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.

9x + 2 < \( \frac{x}{-3} \)
-3 x (9x + 2) < x
(-3 x 9x) + (-3 x 2) < x
-27x - 6 < x
-27x - 6 - x < 0
-27x - x < 6
-28x < 6
x < \( \frac{6}{-28} \)
x < -\(\frac{3}{14}\)