Question

What number should be added to the polynomial x²– 5x + 4, so that 3 is a zero
of polynomial so obtained.

Answer 1

let the number is "k"

ATQ,

3² - 5×3 +4 + k = 0

9-15+4 + k = 0

-2 +k = 0

k = 2


so, 2 should be added to the polynomial.

Answer 2

Hi !

Let the no: to be added be "a"

 x² - 5x + 4 + a = 0

x = 3

p(3) = 0

(3)² - 5*3 + 4 + a = 0

9 - 15 + 4 + a = 0

-2 + a = 0

a = 2

Hence,

The no: to be added to the polynomial is 2