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2 votes
Solve the absolute value equation. |5m + 2| + 5 = 8

2 Answers

5 votes

Begin the solution of |5m + 2| + 5 = 8 by subtracting 5 from both sides:


|5m + 2| = 3


Divide all 3 terms by 5 to isolate m: |m + 2/5| = 3/5


Case 1: m + 2/5 is already positive. The absolute value operator has no bearing. We have m + 2/5 = 3/5, or m = 1/5.


Case 2: (m + 2/5) is negative. Then we have -(m + 2/5) = 3/5, or

-m - 2/5 = 3/5, or

-m = 1, or m=-1


The solution set is {-1, 1/5}. Check both results via substitution.

User Ryancheung
by
7.9k points
4 votes
5m+7=8

5m=1
m=1/5

-5m-2+5=8
-5m+3=8
-5m=5

m=-1
User Barry Franklin
by
8.6k points