Question

What should be subtracted to the polynomial x² – 16x + 30, so that 15 is the zero of the resulting polynomial?
A. 30
B. 14
C. 15
D. 16

Answer 1

Answer:

Step-by-step explanation:

Answer 2

C. 15

Step-by-step explanation:

Let us take f(x) =  x² – 16x + 30 and assume that the number to be subtracted is 'a' such that 15 is the zero of the resulting polynomial.

For f(15) to be a zero of the polynomial, 'a' is to be subtracted from the polynomial.

f(15) = 15² - 16(15) + 30 - a = 0

      225 - 240 +30 - a = 0

      15 - a = 0

      Therefore a = 15

f(x) must be reduced by 15 so that the resulting polynomial has 15 as its zero.

Option C is the answer.