You can put this solution on YOUR website! What is it you want to do with this function? How do a and b relate? Are they supposed to be x-coordinates of the x-intercepts? Are you just supposed to evaluate the function at a and b? Give us something to go on here, please. This note applies to the other two problems that you submitted as well.
You can put this solution on YOUR website! P(x)=2x^3-21x^2-2x+25; a=1,b=2
P(1)=2(1)^3-21(1)^2-2(1)+25
2-21-2+25
2-23+25
=4
P(2)=2(2)^3-21(2)^2-2(2)+25
2(8)-21(4)-4+25
16-84-4+25
-68-4+25
-72+25
=-47