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 equal sign and the answer on the other.

-7b - 8 = \( \frac{b}{2} \)
2 x (-7b - 8) = b
(2 x -7b) + (2 x -8) = b
-14b - 16 = b
-14b - 16 - b = 0
-14b - b = 16
-15b = 16
b = \( \frac{16}{-15} \)
b = -1\(\frac{1}{15}\)

The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:

a = ½(b + d)(h)
a = ½(4 + 9)(2)
a = ½(13)(2)
a = ½(26) = \( \frac{26}{2} \)
a = 13

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

2a - 4a = -2a

The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c²) is equal to the sum of the two perpendicular sides squared (a² + b²): c² = a² + b² or, solved for c, \(c = \sqrt{a + b}\)

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.

(6a)(2ab) - (5a²)(4b)
(6 x 2)(a x a x b) - (5 x 4)(a² x b)
(12)(a¹⁺¹ x b) - (20)(a²b)
12a²b - 20a²b
-8a²b