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.)

-8a(a - x)
-8(2)(2 - 9)
-8(2)(-7)
(-16)(-7)
112

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)(5ab) + (4a²)(8b)
(8 x 5)(a x a x b) + (4 x 8)(a² x b)
(40)(a¹⁺¹ x b) + (32)(a²b)
40a²b + 32a²b
72a²b

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

a = l x w
a = a x b
a = 8 x 5
a = 40

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.

(3a)(5ab) - (8a²)(3b)
(3 x 5)(a x a x b) - (8 x 3)(a² x b)
(15)(a¹⁺¹ x b) - (24)(a²b)
15a²b - 24a²b
-9a²b

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.

-x + 9 < \( \frac{x}{5} \)
5 x (-x + 9) < x
(5 x -x) + (5 x 9) < x
-5x + 45 < x
-5x + 45 - x < 0
-5x - x < -45
-6x < -45
x < \( \frac{-45}{-6} \)
x < 7\(\frac{1}{2}\)