Answer
most hours you can spend walking is 10 hours
Work Step by Step
Let x=number of hours dog walking
then 15-x=number of hours tutoring
$8(15-x) +7.5x\geq115$
Distribute 8: $120-8x+7.5x\geq115$
Simplify: $-0.5x\geq-5$
Divide both sides by -0.5: $\frac{-0.5x}{-0.5}\geq\frac{-5}{-0.5}$
Simplify: $x\leq10$
