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Here's another one:

| 2x - 1 | = 5
What can we say about this blob?

It's either -5 ... or 5:

2x - 1 = -5     or     2x - 1 = 5

Now we solve them!

2x - 1 = -5 ... add 1 to both sides ... 2x = -4 ... divide both sides by 2 ... x = -200-red-vertical-line.gif
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2x - 1 = 5 ... add 1 to both sides ... 2x = 6 ... divide both sides by 2 ... x = 3

{ -2 , 3 }

I'll let you check these - back in the original problem.


YOUR TURN:

Solve | 2 - 5x | = 7