Math
posted by alex on .
What are all values of x for which 2x3 < 7 ?

1, 2, 3, 4

If 2x3 > 0, which means x >or 1.5,
Ms Sue has provided some but not all possible values of x.
First assume 2x3 >0
This requires x > 1.5, and
2x3 < 7
That means x < 5.
Therefore 1.5 < x < 5 are answers.
If 2x < 3, which means x < 1.5,
3  2x < 7
x > 2
Therefore 2 < x < 1.5 are answers
Put them together and you find that 2 < x < 5 is the range of answers.