Can someone answer a b and c please

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

Worth 100 points need the answers asap first row -x^2 2x^2 (x/2)^2 x^2 x is less than 2 x is greater than 2 x is less than or equal to 2 x is greater than or equal to 2 second row -5 -5/2 4 5 •2 is less than x& x is less than 4 •2 is less than or equal to x & x is less than or equal to 4 •2 is less than or equal to x& x is less than 4 •2 is less than x& x is less than or equal to 4

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?