Quadratic equation please help

Write a numerical expression that satisfies all of the following conditions. 1.)the only number used in the expression is 5 2.)at least one exponent other than 1 is used 3.)when the expression is evaluated, the answer is greater than 40 and less than 50

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g