WAEC - Mathematics (1993 - No. 9)
Factorize the expression 2s\(^2\) - 3st - 2t\(^2\).
(2s - t)(s + 2t)
(2s + t)(s - 2t)
(s + t)(2s - 1)
(2s + t)(s -t)
(2s + t)(s + 2t)
Vysvetlenie
2s\(^2\) - 3st - 2t\(^2\)
= 2s\(^2\) - 4st + st - 2t\(^2\)
= 2s(s - 2t) + t(s - 2t)
= (2s + t)(s - 2t)