Example

Solving 9x=8x69x = 8x - 6 by Collecting Variables

To solve 9x=8x69x = 8x - 6, first observe that variable terms appear on both sides of the equation, while the constant 6-6 appears only on the right. Designate the left side as the variable side and the right side as the constant side.

Step 1 — Remove the variable term from the constant side: Since 8x8x is on the constant side, subtract 8x8x from both sides using the Subtraction Property of Equality:

9x8x=8x8x69x - 8x = 8x - 8x - 6

Step 2 — Simplify: On the left, 9x8x=x9x - 8x = x. On the right, 8x8x=08x - 8x = 0, leaving just 6-6:

x=6x = -6

Because the coefficient of xx is already 11, no further division is needed.

Step 3 — Check by substitution: Replace xx with 6-6 in the original equation:

9(6)=?8(6)69(-6) \stackrel{?}{=} 8(-6) - 6

54=?486-54 \stackrel{?}{=} -48 - 6

54=54-54 = -54 \checkmark

Because both sides are equal, x=6x = -6 is confirmed as the correct solution. This example demonstrates that when the variable appears on both sides of an equation, the first step is to subtract the smaller variable term from both sides so that all variable terms are collected onto one side.

0

1

Updated 2026-04-21

Contributors are:

Who are from:

Tags

OpenStax

Elementary Algebra @ OpenStax

Ch.2 Solving Linear Equations and Inequalities - Elementary Algebra @ OpenStax

Algebra

Math

Prealgebra

Related
Learn After