Ответ:

[tex]-\frac{5}{9} (5.4x-1\frac{1}{5} y) - 6.4(-\frac{3}{8}x + 2.5y) = -\frac{5}{9} (\frac{54}{10} x-\frac{6}{5} y) - \frac{64}{10} (-\frac{3}{8}x + \frac{25}{10} y)=-3x+\frac{2}{3}y+\frac{24}{10}x-16y = -3x +2.4x -15\frac{1}{3}y = -0.6x-15\frac{1}{3}y[/tex]

x = -10

y = 0.1

[tex]-0.6x-15\frac{1}{3}y =-0.6*(-10)-\frac{46}{3}*\frac{1}{10} = 6-1\frac{16}{30} = 4\frac{14}{30} = 4\frac{7}{15}[/tex]