Question

Find x. A: 2 square 5 B: 3 square 6 C: 6

Answer 1

Notice they are all right triangles. You will need Pythagorean theorem, which is a² + b² = c²

If you write down all the "equations" you can find, it is the following:

y² + 4² = x²

5² + y² = z²

x² + z² = 9²

Substitute them into one equation:

y² = x² - 4²

z² = 5² + (x² - 4²) Notice that the y² is replaced with what you found above

x² + (5² + x² - 4²) = 9² Notice that the z² is replaced with what's above

Now that it is just one line with one variable, you should be able to find value of x easily.

The answer is 6 if my calculations are correct.