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!!
Answer: 3
Step-by-step explanation:
6y (1)
2 (2)
9x (3)
4 is equal to 2*2 (double the 2 is 4)
