Question

If zeroes of the polynomial "p(x)=-8x^(2)+(k+5)x+36" are negative to each other,then the value of "k" is (a) "-5," (b) "5," (c) "4," (d) "3"

Answer 1

Answer:

(a) -5

Step-by-step explanation:

we know that the negative of co-efficient of x by the co-efficient of x^2 is the sum of the zeroes of the polynomial, that is-

$\alpha$ + $\beta$ = -b/a

so, substituting the terms with the values from the polynomial, we get-

\alpha + \beta = -(k+5)/-8

according to the question, \alpha = - \beta

so, the equation can further be simplified as-

\alpha + (- \alpha ) =  (k+5)/8

0 = (k+5)/8

0*8 = k+5

k = 0 - 5

k = -5