Answer:
Step-by-step explanation:
49%
(a+b)(a-b)=a^2-b^2
The answer is C.
You need you use Pythagoras theorem 2 times to have 2 equations with the same sides i.e. for example a2 + b2 = 81 and a2 - b2 = 9.
You can do it as you have different triangles but with the same sides.