WAEC - Mathematics (1998 - No. 16)
For what value of x is the expression
x - 5x2 - 2x - 3
not defined?3, 1
-1, -3
-1, 3
3, -2
1, -3
Explicació
x2 - 2x - 3 = 0
x2 - 3x + x - 3 = 0
x(x - 3) + (x - 3) = 0
(x + 1)(x - 3) = 0
x = -1 or 3
x2 - 3x + x - 3 = 0
x(x - 3) + (x - 3) = 0
(x + 1)(x - 3) = 0
x = -1 or 3