WAEC - Further Mathematics (2024 - No. 16)
If kx\(^2\) is a term in the binomial expansion of (1 - 2x)\(^4\), find the value of k.
-24
-8
8
24
คำอธิบาย
Given: (1 - 2x)\(^4\), find kx\(^2\)
Using, \(^4_rCr(-2x)^r(1)^r\)
Where r is from x\(^2\) = 2
\(^4_2Cr(-2x)^2(1)^2\) = 6 * 4x\(^2\) = 24x\(^2\)
kx\(^2\) = 24x\(^2\)
Therefore, k = 24.