Question

What is the fifth term of (2x + y)^8?

Answer 1

Answer:

Expansion for there will be 9 terms.

(a+b) ^n =nco a^n b^o+ nc1 a^(n-1) b^1+nc2 a^(n-2) b^2+nc3 a(n-3) b^3+nc4  a^(n-4) b^4+...........................ncn a^o b^n.

5th term of  (2x+y)^8 = ?  

5th term is nC4 a^(n-4) b^4

a=2x, b=y, n=8

therefore 8C4 (2x)^(8-4)  (y)^4

8!/((8-4)! 4!) (2x)^4 y^4

40320/576  (16 x^4 ) (y^4)

70 (16x^4)(y^4)

1120 X^4 Y^4

Step-by-step explanation: