Question

Verify whether 2,-5 and 3 are the zeroes of the polynomial p(x) =x^3 -5x^2 -4x+ 20 or not

Answer 1

Answer:

2 is a zero of the polynomial p(x) = x³ -5(x)² -4(x)+ 20, but -5 and 3 are not.

Step-by-step explanation:

First, we will try for 2

p(2) =2³ -5(2)² -4(2)+ 20

       = 8 - 20 - 8 +20

       = 0

Hence, 2 is a zero of the polynomial p(x) = x³ -5(x)² -4(x)+ 20.

Next, we have -5

p(-5) = -5³ -5(-5)² -4(-5)+ 20

        = -125 - 125 + 20 +20

        = -250 +40

        = -210

        ≠ 0

Hence, -5 is not a zero of the polynomial p(x) = x³ -5(x)² -4(x)+ 20.

Finally, we will check for 3

p(3) = 3³ -5(3)² -4(3)+ 20

       = 27 - 45 - 12 +20

       = -10

       ≠ 0

Hence, 3 is not a zero of the polynomial p(x) = x³ -5(x)² -4(x)+ 20.