Find the least value of $b$ such that $b^2+2b-15 \le 0$.
To do that, I can first factor the expression as $(b+5)(b-3)$. Then, I can see that the expression is zero when $b=-5$ or $b=3$, and it is negative when $b$ is between those values. So, the least value of $b$ that satisfies the inequality is $b=-5$.

