3(2x^3+3y^2) (2x^3 -3y^2)
So times $64.80 by 2.5. You minus 20 from that, so that the RacerZ is $142. You take that $142 and times that by 1.09. You get 154.78. Therefore;
Speedmonster- 64.80
RacerZ- 142
Swiftee-154.78
Hope this helps. :)
The vertex is the point where the function changes direction, in this case from growing to decrease. That is the point wiht x-coordinate 4 and y-coordinate 1, so the point is (4,1).
