6h - 7 < 5
6h < 5
This means that 6 times h is less than 5.
h < 2 means that as long as h is less than 2, this inequality will be true.
A counterexample would be 1.
6h < 5
6(1) < 5
6 × 1 < 5
6 < 5
6 is not less than 5, therefore that inequality is not true and 1 proves to be a counterexample.