SOLUTION: i don't understand ow to solve these problems. ex:// 2|3m-1|-12=4 my teacher said we have to get the brackets by themselves and then solve,but i don't understand. Please H

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Question 9702: i don't understand ow to solve these problems.
ex:// 2|3m-1|-12=4
my teacher said we have to get the brackets by themselves and then solve,but i don't understand.
Please Help
Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website!
Ok, here we go: Get the bars by themselves.
2|3m-1|-12 = 4 Add 12 to both sides.
2|3m-1| = 16 Divide both sides by 2.
|3m-1| = 8 Remove the absolute-value bars and write two equations.
1) 3m-1 = 8 and
2) 3m-1 = -8
Solve the two equations for m.
1) 3m-1 = 8 add 1 to both sides.
3m = 9 Divide both sides by 3.
m = 3
2) 3m-1 = -8 Add 1 to both sides.
3m = -7 Divide both sides by 3.
m = -7/3
Check: Remember that |8| = 8 and |-8| = 8
For m = 3:
2|3*3-1|-12 = 4
2|9-1| - 12 = 4
2|8| - 12 = 4
2(8) - 12 = 4
16 - 12 = 4
4 = 4
For m = -7/3:
2|3(-7/3)-1|-12 = 4
2|-7-1| - 12 = 4
2|-7-1| - 12 = 4
2|-8| - 12 = 4
2(8) - 12 = 4
16 - 12 = 4
4 = 4