Помогите пожалуйста ответить заранее спасибо

1) $\frac{4*c+3*y}{c^{2} -y^{2}} - \frac{3}{c-y}= \frac{4*c+3*y-3*(c+y)}{ c^{2}- y^{2} } = \frac{c}{ c^{2}- y^{2} }$
2) $\frac{c}{ c^{2}- y^{2} } + \frac{1}{y-c}= \frac{c}{ c^{2}- y^{2} } - \frac{1}{c-y} = \frac{c-1*(c+y)}{ c^{2} - y^{2} } = \frac{-1*y}{ c^{2} - y^{2} } }$
3) $\frac{-1*y}{ c^{2}- y^{2} }- \frac{4}{5*y+5*c} = \frac{-5*y-4*(c-y)}{5*( c^{2} - y^{2} )} = \frac{-y-4*c}{5*( c^{2} - y^{2} )}= \frac{4*c-y}{5*( y^{2} - c^{2} )} .$