Question

помогите пожалуйста!​

Answer 1

$\displaystyle\bf\\\frac{1}{5} s^{2} +\frac{2}{5} sy+\frac{1}{5} y^{2} =\frac{1}{5}(s^{2}+2sy+y^{2} )=\frac{1}{5}(s+y)^{2} =\frac{1}{5} (s+y)(s+y)$