For each question we must apply the Pythagorean theorem and clear the value of x.
question 5
x = root (14 ^ 2 + 16 ^ 2)
x = root (452)
x = 2raiz (113)
question 6
x = root (8 ^ 2 + 15 ^ 2)
x = 17
question 7
x = root (12 ^ 2 + 12 ^ 2)
x = root (2 * (12 ^ 2))
x = 12raiz (2)
question 8
x = root (18 ^ 2 - 9 ^ 2)
x = root (243)
x = 9raiz (3)