Solve the quadratic ( ^ means to the power of)

n^2 + 21n = 0

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

Find the missing dimension extra points

Determine the required value of the missing probability to make the distribution a discrete probability distribution. x p(x) 3 0.23 4 ? 5 0.51 6 0.08 p(4) = nothing  (type an integer or a decimal.)