How do you solve abs(5x+3)=abs(2x-1)?

1 Answer
Noah G
Aug 14, 2016

Case 1: Both Absolute Values are positive

5x + 3 = 2x - 1

3x = -4

x = -4/3

Case 2: The left absolute value is negative

-(5x + 3) = 2x - 1

-5x - 3 = 2x - 1

-7x = 2

x = -2/7

Case 3: The right absolute value is negative

5x + 3 = -(2x - 1)

5x + 3 = -2x + 1

7x = -2

x = -2/7

As you can see, whether the absolute value on right is negative and the other positive or the absolute value on left is negative and the other positive, both scenarios will give the same result.

Let's just check our solutions to make sure none are extraneous.

|5(-4/3) + 3| =^? |2(-4/3) - 1|

Doing all the fractal operations on this, you will find that this, as well as the other solution, x = -2/7, work in the original equation.

Hence, our solution set is {x = -2/7, -4/3}.

Hopefully this helps!

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