Question

What is the value of x to the nearest tenth? A. 6.0 B. 13.4 C. 26.8 D. 30.0

Answer 1

Use the Pythagorean theorem:

$\left(\dfrac{1}{2}x\right)^2+12^2=18^2\\\\\dfrac{1}{4}x^2+144=324\ \ \ |-144\\\\\dfrac{1}{4}x^2=180\ \ \ \ |\cdot4\\\\x^2=720\to x=\sqrt{720}\\\\\boxed{x\approx26.8}$