Example

Solving 5(n4)4n=8{}5(n - 4) - 4n = -8 by Simplifying First

To solve the equation $5(n - 4) - 4n = -8$, follow a step-by-step strategy to simplify both sides before isolating the variable:

  1. Simplify the left side: First, use the distributive property to eliminate the parentheses by multiplying 5 by each term inside: $5n - 20 - 4n = -8. Next, use the Commutative Property to rearrange the terms so like terms are grouped together ($5n - 4n - 20 = -8), and combine those like terms to fully simplify the left side to n20n - 20. The right side is already simplified as 8-8. The equation is now n20=8n - 20 = -8.
  2. Isolate the variable: Undo the subtraction by applying the Addition Property of Equality. Add 20 to both sides (n20+20=8+20n - 20 + 20 = -8 + 20) and simplify to find the value of nn: n=12n = 12.
  3. Check the solution: Substitute 12 for nn back into the original equation to confirm it produces a true statement: $5(12 - 4) - 4(12) = -8, which simplifies to $5(8) - 48 = -8, and then $40 - 48 = -8,resultinginthetruemathematicalstatement, resulting in the true mathematical statement -8 = -8.Thus,. Thus, n = 12$ is indeed the correct solution.

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