You can’t factor 31 since it’s a prime number luv
This is called the Pythagorean theorem : a ² + b ² = c ². You can substitute any of the variable with any of the known numbers and then you all you have to do is isolate the variable. I hope that helps!!
If you are asking 7/8 - 1/x= 3/4,
first put 3/4 to 6/8 to make it easier.
Move the 7/8 over to the right. You will get 1/x=-1/8.
Simplify, it is x=-8.
Check=7/8 - 1/8=6/8
It checks out.
0.865, 0.4444, -6.37, -11.11
Rational are decimals / fractions