Vocabulary

Variable: A symbol, usually a letter, used to represent a number in mathematical expressions or sentences.

Equation: A mathematical sentence stating that two quantities are equal.

Concept

Solve two-step equations of the form ax ± b = c, where a, b, c, and x are rational numbers.

Rules

1. Substitute the variable in the equation with its given value. 
2. Follow the order of operations to simplify. 

Example

Solve for x.

4x + 2 = 18

Solution

To solve, you use reverse order of operations. Subtract 2 on both sides.

4x + 2 = 18

4x + 2 - 2 = 18 - 2

4x = 16

Divide both sides by 4 

$\frac{4}{4}$x = $\frac{16}{4}$

x = 4

Pre-requisite Skills

Solve Two-Step Equations (8.2.2)

Solve Equations with Rational Coefficients (8.2.1)