X intercepts for f(x)= -2x^2+8x-8

Tim's phone service charges $26.39 plus an additional $0.21 for each text message sent per month. if tim's phone bill was $31.64, which equation could be used to find how many text messages, x, tim sent last month?

Two florida panthers were weighed. one weighs 6x+21 pounds and the two together weigh 14x+11 pounds how much does he other panther weigh alone

Evaluate the function , when d = {9, 15, 30}. r = {5, 7, 12} r = {6, 10, 15} r = {6, 10, 20} r = {5, 12, 20}