Question

Find the value of x. If your answer is not an integer, express it in simplest radical form.

according to the back of my book, the answer is 8√5 but i’m not sure
how to get it.

Answer 1

x = 8√5

Explanation:

for right triangle

c^2 = a^2 + b^2

with c is the hypotenuse; a & b are the other sides

(4 + 16)^2 = (4√5)^2 + x^2

400 = 80 + x^2

x^2 = 320

x^2 = 64(5)

√x^2 = √64(√5)

x = 8√5