The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.

A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).

To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -27 as well and sum (Inside, Outside) to equal -6. For this problem, those two numbers are -9 and 3. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 6y - 27
y² + (-9 + 3)y + (-9 x 3)
(y - 9)(y + 3)

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(7 + 7)(5)
a = ½(14)(5)
a = ½(70) = \( \frac{70}{2} \)
a = 35

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.

(4a)(8ab) - (8a²)(2b)
(4 x 8)(a x a x b) - (8 x 2)(a² x b)
(32)(a¹⁺¹ x b) - (16)(a²b)
32a²b - 16a²b
16a²b