JAMB - Mathematics (2023 - No. 3)
Let '*' and '^' be two binary operations such that a * b = a\(^2\)b and a ^ b = 2a + b. Find (-4 * 2) ^ (7 * -1).
-49
64
113
15
Explicació
Given that, a * b = a\(^2\)b and a ^ b = 2a + b
(-4 * 2) = (-4)\(^2\) x 2 = 16 x 2 = 32
(7 * -1) = 7\(^2\) x (-1) = 49 x (-1) = -49
∴ (-4 * 2) ^ (7 * -1) = 2(32) + (-49) = 64 - 49 = 15
(-4 * 2) = (-4)\(^2\) x 2 = 16 x 2 = 32
(7 * -1) = 7\(^2\) x (-1) = 49 x (-1) = -49
∴ (-4 * 2) ^ (7 * -1) = 2(32) + (-49) = 64 - 49 = 15