JAMB - Mathematics (1998 - No. 9)
Factorize r2 - r(2p + q) + 2pq
(r - 2q)(2r - p)
(r - p)(r + p0
(r - q)(r - 2p)
(2r - q)(r + p)
คำอธิบาย
r2 - r(2p + q) + 2pq = r2 - 2pr -qr + 2pq
= r(r - 2p) - q(r - 2p)
= (r - q)(r - 2p)
= r(r - 2p) - q(r - 2p)
= (r - q)(r - 2p)