Question

Найдите значение выражения:
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Answer 1

Объяснение:

1)\

$\frac{y-25}{5y-25}+\frac{3y+5}{y^2-5y} =\frac{y-25}{5*(y-5)} +\frac{3y+5}{y*(y-5)} =\frac{y*(y-25)+5*(3y+5)}{5y*(y-5)} =\frac{y^2-25y+15y+25 }{5y*(y-5)}=\\=\frac{y^2-10y+25}{5y*(y-5)}=\frac{(y-5)^2}{5y*(y-5)}=\frac{y-5}{5y}=\frac{2,5-5}{5*2,5}=\frac{-2,5}{12,5}=-0,2.$

2)

$\frac{2}{y^2-yx} -\frac{2}{yx-x^2}= \frac{2}{y*(y-x)}-\frac{2}{x*(y-x)} =\frac{2*x-2*y}{xy*(y-x)} =\frac{-2*(y-x)}{xy*(y-x)}=-\frac{2}{xy}=\\=-\frac{2}{2*(-3)} = -\frac{2}{-6} =\frac{1}{3}.$