Question from Heinamann P2 Book: p48 Q12 :
The coefficients of the x and x2 terms in the expansion of (1+kx)n are 44 and 924 respectivley. Find the values of the constants k and n.
(Answer in back: n = 22, k = 2)
Can someone explain to me how to do this? The thing is, i arrived at the answer but i dont know why i did because when i carried out the expansion and equated the coefficients with their respective expansions, i acciently left out the 2! value for the x2, but somehow arrived at the answer.
When i re-tried putting in the missing 2!, i did not get the correct answer.
Could someone help me out!