The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

x² + 7x + 12 = 0
(x + 3)(x + 4) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (x + 3) or (x + 4) must equal zero:

If (x + 3) = 0, x must equal -3
If (x + 4) = 0, x must equal -4

So the solution is that x = -3 or -4

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.

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 -4 as well and sum (Inside, Outside) to equal -3. For this problem, those two numbers are -4 and 1. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 3y - 4
y² + (-4 + 1)y + (-4 x 1)
(y - 4)(y + 1)

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).

A line segment is a portion of a line with a measurable length. The midpoint of a line segment is the point exactly halfway between the endpoints. The midpoint bisects (cuts in half) the line segment.