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.

A monomial contains one term, a binomial contains two terms, and a polynomial contains more than two terms.

The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)² : a = π r².

Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other. Same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°).

To solve this equation, isolate the variable for which you are solving (b) on one side of the equation and put everything else on the other side.

7b + 4z = 9b + 8z + 1
7b = 9b + 8z + 1 - 4z
7b - 9b = 8z + 1 - 4z
-2b = 4z + 1
b = \( \frac{4z + 1}{-2} \)
b = \( \frac{4z}{-2} \) + \( \frac{1}{-2} \)
b = -2z - \(\frac{1}{2}\)