Question

If (x – ½) and (x-2) are the factors of px2+5x + r, find p and r . Also find p -r .

Answer 1

p = -2, r = -2 and p-r = 0.

Explanation:

(x - 1/2)(x - 2)

= x^2 - 2x - 1/2x + 1

= x^2 - 5/2x + 1

= 2x^2 - 5x + 2

= -2x^2 + 5x - 2

Comparing this with

px^2 + 5x + r

we see that p = -2, r = -2 and p-r = 0.