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:

b² - 2b - 10 = -b + 2
b² - 2b - 10 - 2 = -b
b² - 2b + b - 12 = 0
b² - b - 12 = 0

Next, factor the quadratic equation:

b² - b - 12 = 0
(b + 3)(b - 4) = 0

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

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

So the solution is that b = -3 or 4

Angles around a line add up to 180°. Angles around a point add up to 360°. When two lines intersect, adjacent angles are supplementary (they add up to 180°) and angles across from either other are vertical (they're equal).

To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses.

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.

5a + 7a = 12a

An equation is two expressions separated by an equal sign. The key to solving equations is to 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.