We can check our answers by substituting them for b in the given equation. Let's start with b=- 15.
8^2+b^2=17^2
8^2+( - 15)^2? =17^2
8^2+15^2? =17^2
64+225? =289
289=289 ✓
We obtained a true statement, so b=- 15 is a solution of the equation. Let's check if b=15 is also a solution.
8^2+b^2=17^2
8^2+ 15^2? =17^2
289=289 ✓
Again we got a true statement, so we know that b=15 is a solution of the equation.
