Answer:
The answer is 21
Step-by-step explanation:
I searched it up.
21
(9x2 + 6x – 7) + (-9x - 5) = 21
sqrt(20)
The two perpendicular side lengths are equal, so using Pythagoras theorem:
x = sqrt( sqrt(10)^2 + sqrt(10)^2 )
x = sqrt(10 + 10)
x = sqrt(20)
The Answer 3182121