As I look into the problem with a deeper meaning then math I realize this answer can be not as hard as it appears and it could be hard to answer it
Multiply out
remember thatn (-) times (+)=(-) so
+3 times -4=-12
-12x=0
the only number that will work is 0 since 0 times anything=0
x=0
The length is 10 and the area is 100 because 6,8,10 is a pythagorean triple. 36 + 64 = 100 and the square root of 100 is 10. 10 ^ 2 is the area which is 100. If this is right could you possibly give me brainliest? Hope this helped.