Which expression is equivalent to (-5 x 2^2 x 2^0)^-2

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Cot(90° − x) = 1 the value of x that satisfies this equation is °. a. 60 b. 135 c. 225 d. 315

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?