85.9k views
5 votes
1/3 |2x+3|-1 is less than or equal to 8

1 Answer

3 votes

(1)/(3)|2x+3|-1\leq8

Adding 1 to both sides gives


(1)/(3)|2x+3|\leq9

and then multiplying both sides by 3 gives


|2x+3|\leq27

At this point, this absolute value inequality can be decomposed into two separate inequalities


\begin{gathered} -(2x+3)<27 \\ (2x+3)<27 \end{gathered}

We first solve the first inequality.

Multiplying both sides by -1 reverses the sign of the inequality and gives


2x+3>-27

subtracting -3 from both sides we get


2x>-30

and finally dividing both sides by 2 gives


x>-15.

That is the first solution, the second solution is given by the second inequality 2x+ 3 <27.

Subtracting 3 from both sides and then dividing the equation by 2 gives


x<12

Hence, the solution to our inequality is

[tex]-15

User Floris
by
4.4k points