JAMB - Mathematics (1984 - No. 33)
The larger value of y for which (y - 1)2 = 4y - 7 is
2
4
6
7
8
Vysvětlení
(y - 1)2 = 4y - 7
y2 - 2xy + 1 = 4y - 7
y2 - 6y + 8 = 0
(y - 4)(y - 2)
y = 4 or 2 = 4
y2 - 2xy + 1 = 4y - 7
y2 - 6y + 8 = 0
(y - 4)(y - 2)
y = 4 or 2 = 4