Solution: Substitute $ a = 5 $ into $ 5(5 + b) = 120 $. Simplify: $ 25 + 5b = 120 $. Subtract 25: $ 5b = 95 $. Divide by 5: $ b = 19 $.

Fri, 17 Apr 2026 18:24:04 +0000

How to Solve the Equation $ 5(5 + b) = 120 $: A Step-by-Step Guide Solving linear equations efficiently is a key skill in algebra, and one of the most common types involves substitution and simplification. One such example is solving the equation: $$
5(5 + b) = 120
$$ This equation is easy to tackle when broken down step by step. In particular, substituting $ a = 5 $ simplifies the expression cleanly and leads directly to the solution. Let’s walk through the process.