Q.

If the constant term in the binomial expansion of x5224xl9is -84 and the coefficient of x3l is 2αβ where β<0 is an odd number, then αl-β is equal to _____

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

answer is 98.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

detailed_solution_thumbnail

r=npp+q where n=9,p=52,q=l=455+2lr=455+2l& 9Cr29r(4)r=84 (r is odd) is satisfied by r=3,l=5
coefficient of x3l is 2αβ(β<0,β is odd )
coefficient of Term containing x15 in x5224x59 is Tr+1 where r=952+1552+5=7515=5
T6=9C5x52244x552αβ=9C512445=269C5=26(18×7)=262×32×7=277×32
So, β=63,α=7,
G.E=|αlβ|=|7(5)+63|=98

Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon