Radius question. Can anyone help answer this please? Please could you also help explain?

Evaluate the expression for the given value of the variable 2×(c2-5) for c=4

Aportion of a hiking trail slopes downward at about an 84° angle. to the nearest tenth of a flot, what is the value of x, the distance the hiker traveled along the path, if he has traveled a horizontal distance of 120 feet? a. 143.3 b. 12.5 c. 120.7 d. 130.2

Which expression is equivalent to (4 +6i)^2? ? -20 + 48i 8 + 12i 16 - 36i 20 + 48i