We can check our answers by substituting them for a in the given equation. Let's start with a=- 9.
a^2+40^2=41^2
( - 9)^2+40^2? =41^2
9^2+40^2? =41^2
81+1600? =1681
1681=1681 ✓
Since we got a true statement, we know that a=- 9 is a solution of the equation. Let's check if a=9 is also a solution.
a^2+40^2=41^2
9^2+41^2? =41^2
1681=1681 ✓
We obtained a true statement, so we know that a=9 is also a solution of the equation.
