Answer
$y^5-5y^4x+10y^3x^2-10y^2x^3+5yx^4-x^5$
Work Step by Step
The coefficients in the the $n=
5
$ row of Pascal's Triangle are $\{
1,5,10,10,5,1
\}$. Using these as the coefficients of the terms that follow the pattern in expanding binomials, the expression $
(y-x)^5
$ expands to
\begin{array}{l}
y^5-5y^4x+10y^3x^2-10y^2x^3+5yx^4-x^5
.\end{array}
