Twice the sum of a number and 3 is 20. The algebraic equation is:

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

Find the roots of the polynomial function f(x) = x^3 + 2x^2 + x

Okay so i didn't get this problem petro bought 8 tickets to a basketball game he paid a total of $200 write an equation to determine whether each ticket cost $26 or $28 so i didn't get this question so yeahyou have a good day.