Question

Помогите а и б плиз дам 39 баллов

Answer 1

а) $= frac{a*(a+3)-3(a+3)+18}{a+3} * frac{ a^{2}+6a+9 }{ a^{2}+9 } * frac{1}{a-3} = frac{ a^{2}+3a-3a-9+18 }{a+3} * frac{ (a+3)^{2} }{ a^{2}+9 } * frac{1}{a-3} =$$( a^{2} +9)* frac{a+3}{ a^{2}+9 } * frac{1}{a-3} =(a+3)* frac{1}{a-3} = frac{a+3}{a-3}$

б) =$( frac{x}{ y^{2}+xy } + frac{x-y}{x(x-y)}):( frac{ y^{2} }{x( x^{2} - y^{2}) } + frac{1}{x-y} = ( frac{x}{ y^{2}+xy } + frac{1}{x}) :( frac{ y^{2} }{x(x-y)(x+y)} + frac{1}{x-y} )$=$frac{ x^{2} + y^{2}+xy }{x( y^{2}+xy) } : frac{ y^{2}+x(x+y) }{x(x+y)(x-y)} = frac{ x^{2} + y^{2}+xy }{xy(y+x)} : frac{ y^{2}+ x^{2} +xy }{x(x+y)(x-y)} =$$frac{x^2+ y^{2}+xy } {xy(y+x)} * frac{x(x+y)(x-y)}{y^2+x^2+xy}= frac{1}{y} (x-y)= frac{x-y}{y}$