Question

преобразуйте в многочлен (x -две пятых y )*(x-две пятых y)

Answer 1

$(x - \frac{2}{5} y)(x - \frac{2}{5} y) = \\ {x}^{2} - \frac{2}{5} xy - \frac{2}{5} xy + \frac{4}{20} {y}^{2} =$
${x}^{2} - \frac{4}{5} xy + \frac{4}{20} {y}^{2} = \\ {x}^{2} - \frac{4}{5} xy + \frac{1}{5} {y}^{2}$