Respuesta :

Answer: 9

Step-by-step explanation:

Use Pythagorean's Theorem for a right triangle.

[tex]a^2+b^2=c^2[/tex]

[tex](\sqrt{63}) ^2+x^2=12^2\\63+x^2=144\\x^2=81\\x=9[/tex]

X=9

A squared + b squared = c squared

C is the hypotenuse (the side opposite of the right angle)

X*2 + square root of 63 squared = 12*2
Squaring 63 would cancel out with the square root. You are left with x*2 + 63 = 144. 144-63= 81. X*2=81 ; square root both sides. You are now left with x=9