Question

if p-q+r=0 then a zero of the polynomial px² +qx+r is, a=0, b=1, c=-1, d=none of these​
explanation of full solution

Answer 1

p - q + r = 0 (Given)

=> q = p + r

∴ px² + qx + r

=> px² + (p + r)x + r = 0

=> px² + px + rx + r = 0

=> px(x + 1) + r(x + 1) = 0

=> (x + 1)(px + r) = 0

=> x = - 1, - r/p

Therefore, one zero is (- 1) [C].

ALITER:

Assume that p = r = 1, so q = 2

∴ Our reqd expression is => x² + 2x + 1 = 0

=> (x + 1)² = 0

=> x = - 1, - 1

Therefore, C is correct.

[You can proceed with other values of p, r also.]