What is the equation of the line?

Astore sells two types of radios. one type sells $87 and the other for $119. if 25 were sold and the sales were $2495, how many of the $87 radios were sold a) 5 b) 20 c) 15 d)10

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1

Pranza plotted point a in the coordinate plane below.