How do you find the 4th term in the expansion of (4y+x)^4?

1 Answer
Aug 4, 2016

16yx^3.

Explanation:

The (r+1)^(th) term T_(r+1), in the expansion of (a+b)^n is,

T_(r+1)=""^nC_r*a^(n-r)*b^r

So, in our case, for the read. 4^(th) term, T_4 we have,

r=3, n=4, a=4y, and, b=x

:. T_4=""^4C_3*(4y)^(4-3)*x^3

T_4=4*4y*x^3=16yx^3