Answer
$0.04x^2-0.56y+1.96y^2$
Work Step by Step
Using $(a+b)^2=a^2+2ab+b^2$ or the square of a binomial, the given expression, $
(0.2x-1.4y)^2
,$ is equivalent to
\begin{array}{l}\require{cancel}
(0.2x)^2+2(0.2x)(-1.4y)+(-1.4y)^2
\\\\=
0.04x^2-0.56y+1.96y^2
.\end{array}