2014
Mathematics
JAMB
A binary operation * is defined by x * y = xy. If x * 2 = 12 - x, find the possible values of x
A.
3,4
B.
3,-4
C.
-3,4
D.
-3,-4
Correct Answer: 3,-4
Explanation
x * y = xy x * 2 = 12 - x Thus by comparison, x = x, y = 2 But x * y = x * 2 xy = 12 - x x2 = 12 - x x2 + x - 12 = 0 x2 + 4x - 3x - 12 = 0 x(x + 4) - 3(x + 4) = 0 (x - 3)(x + 4) = 0 x - 3 = 0 or x + 4 = 0 So x = 3 or x = -4
x * y = xy x * 2 = 12 - x Thus by comparison, x = x, y = 2 But x * y = x * 2 xy = 12 - x x2 = 12 - x x2 + x - 12 = 0 x2 + 4x - 3x - 12 = 0 x(x + 4) - 3(x + 4) = 0 (x - 3)(x + 4) = 0 x - 3 = 0 or x + 4 = 0 So x = 3 or x = -4THIS WEEK's
Latest Articles
Top-Scorer Okoro Uchechukwu Solomon Reveals How He Scored 337 in JAMB
by samuel olalekan adeyemi
Bouncing Back: How Samuel Isaac Overcame Setbacks to Score 265 in JAMB and What He Learned
by samuel olalekan adeyemi
Managing Stress During Exams: Practical Tips for Students
by samuel olalekan adeyemi
