How do you find the 2nd term in the expansion of (y-2x)^4(y2x)4?

1 Answer
Sep 1, 2016

"The reqd. term"=-8y^3xThe reqd. term=8y3x.

Explanation:

In the Binomial Expansion of (a+b)^n(a+b)n, the general (r+1)^(th)(r+1)th term,

i.e., T_(r+1)Tr+1, is given by,

T_(r+1)=""_nC_r*a^(n-r)*b^rTr+1=nCranrbr.

In our example, n=4, a=y, b=-2x, r+1=2, i.e., r=1n=4,a=y,b=2x,r+1=2,i.e.,r=1

:. T_(1+1)=T_2=""_4C_1*y^(4-1)*(-2x)^1

=4*y^3*(-2x)

=-8y^3x.