How do you solve abs(x-3)<4|x3|<4?

1 Answer

-1 < x < 71<x<7

Explanation:

Absolute value functions can be split up into two functions; represented in variable form, it would look like

| a - b | < c|ab|<c

becomes

a - b < cab<c and a - b > - cab>c

So, you have

| x - 3 | < 4|x3|<4

can be split up into

x - 3 < 4x3<4 and x - 3 > - 4x3>4

Now we can solve each inequality to get

x - 3 < 4x3<4 -> add 3 to both sides

x - cancel(3) + cancel(3) < 4 + 3

x<7

and

x - 3 > - 4 -> add 3 to both sides to get

x - cancel(3) + cancel(3) > -4 + 3

x>-1

so your answer would be

x > - 1
x < 7

or

-1 < x < 7