Math Questions and Answers

Start Your Free Trial

How do you solve the equation l2-3xl> 4 in the real number system? Its supposed to be the absolute value of 2 minus 3x greater than or equal to 4.

Expert Answers info

jeew-m eNotes educator | Certified Educator

calendarEducator since 2012

write1,657 answers

starTop subjects are Math, Science, and Social Sciences

l2-3xl> 4


First we need to define l2-3xl . l2-3xl is always positive,

when l2-3xl > 0 then l2-3xl = 2-3x

Then 2-3x > 0 nad it gives 2/3 > x


when l2-3xl < 0 then l2-3xl = -(2-3x)

Then -(2-3x)>0 and it gives x > 2/3


So when x<2/3 then l2-3xl = 2-3x and when x>2/3 then l2-3xl = -(2-3x)


l2-3xl> 4

When `x<2/3`


   `2-4 > 3x`

     `-2/3 > x`


When` x>2/3`


        `3x > 4+2`

          `x > 2`


So the answers for the inequality is;

`x<-2/3 and x>2 `

`x in (-oo,-2/3) U (2,oo) `


check Approved by eNotes Editorial