Question

If p(x)=5x -4x^2+3 , find p(2)-p(-1)​

Answer 1

p(2)=5(2)-4(4)+3

=20-16+3

=7

p(-1)=5(-1)-4(1)+3=-5-4+3=-6

7-(-6)=13

Answer 2

p(x)=5×-4x²+3

p(2)=5×-4x×(2)²+3

=5x-4x×4+3

=5x-8x+3

=3x-3

=0

p(-1)=5×-1-4(-1)²+3

=5-4-1+3

=9-4

5

hence, p(2) is a polynomial