Answer: y should be in the interval (0.4, 4)
Explanation:
The binomial 5y - 7 is in the interval (-5, 13) if and only if
-5 < 5y - 7 < 13
Solving the inequalities in this form is the same as solving equation. So, we add all sides of the inequalities by 7 so that
2 < 5y < 20
Then, we divide both sides by 5 to get the following inequalities
0.4 < y < 4
Hence y should be in the open interval (0.4, 4).
