Question

Solve: |2x - 7| < 13
A. x < 10
B. x > 10 and x < -3
C. -3 < x < 10
D. x > -3

Answer 1

In general if you have an inequality of the form |ax + b| < c
Then it is equivalent to -c < ax + b < c
which is equivalent to -c - b < ax < c - b
which is equivalent to -(c + b)/a < x < (c - b)/a

Answer 2

thank u so much! :)

Answer 3

yw

Answer 4

Actually, let me make one last correction:
For example, if you have |3x + 9| < 12, then
it is equivalent to -12 < 3x + 9 < 12
which is equivalent to -12 - 9 < 3x < 12 - 9
which is equivalent to -21 < 3x < 12 - 9
which is equvalent to -21/3 < x < 3/3
so -7 < x < 1 is the solution