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Finding x Determine x if |3x+6|=9.

Expert Answers

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We have to solve |3x+6|=9

As the absolute value of (3x + 6) is equal to 9, the actual value of 3x + 6 can be 9 or -9.

This gives 3x + 6 = 9

=> x = 3/3 = 1

and 3x + 6 = -9

=> 3x = -15

=> x = -5

The required values of x are x = 1 and x = -5.

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To solve this, you need to split your first equation into two equations.  This is because |3x+6| can equal 3x + 6 or it can equal -(3x+6) which is -3x - 6.

So you need to solve two equations: 3x + 6 = 9 and -3x - 6 = 9.

Now it's simple:

3x + 6 = 9

3x = 3

x = 1

-3x - 6 = 9

-3x = 15

x = -5

So the answer is that x = -5,1

Approved by eNotes Editorial Team