To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)

c(c - z)
1(3)(3 - 8)
1(3)(-5)
(3)(-5)
-15

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.

2a⁸ + 4a⁸ = 6a⁸

A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.

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).

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:

x² - 6x - 19 = -2x + 2
x² - 6x - 19 - 2 = -2x
x² - 6x + 2x - 21 = 0
x² - 4x - 21 = 0

Next, factor the quadratic equation:

x² - 4x - 21 = 0
(x + 3)(x - 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (x + 3) or (x - 7) must equal zero:

If (x + 3) = 0, x must equal -3
If (x - 7) = 0, x must equal 7

So the solution is that x = -3 or 7