Question

The sum of zeros of polynomial x²-2x-8 will be: (A) -2 (C) 2 B-8 (D) 8​

Answer 1

the sum of zeros of polynomial x²-2x-8 = -2

Answer 2

Given :-

x² - 2x - 8

To Find :-

Quadratic polynomial whose zeroes are 2α and 2β

Solution :-

x² - 2x - 8

x² - (4x - 2x) - 8

x² - 4x + 2x - 8

x(x - 4) + 2(x - 4)

(x - 4)(x + 2)

So,

Either

x - 4 = 0

x = 4

or,

x + 2 = 0

x = -2

Now

Sum of zeroes = -b/a

Sum = -(-2)/1

Sum = 2/1

Sum = 2