Three students ordered wings that cost $21 and french fries for 6$. if they split the bill equally how much did each student pay

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

What is x and y intercepts for y=x+7

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