The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

a² - 7a - 10 = -a - 3
a² - 7a - 10 + 3 = -a
a² - 7a + a - 7 = 0
a² - 6a - 7 = 0

Next, factor the quadratic equation:

a² - 6a - 7 = 0
(a + 1)(a - 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 1) or (a - 7) must equal zero:

If (a + 1) = 0, a must equal -1
If (a - 7) = 0, a must equal 7

So the solution is that a = -1 or 7

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 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.

(9a)(6ab) + (3a²)(8b)
(9 x 6)(a x a x b) + (3 x 8)(a² x b)
(54)(a¹⁺¹ x b) + (24)(a²b)
54a²b + 24a²b
78a²b

A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.