Помогите решить!!! 7 класс
1) 2ab+a^2/2b * 2b/2a^2+a
2) (x^2-y^2) : (x+2)^2/2x
3) 2m^2 -18/m * 2m/m+3 + 36m/m-3
4)(y/x - 2 + x/y) * x^2/x^2-y^2
5)(25/a^3-25a + 1/a+5) : (a-5/a^2+5a - a/25+5a)
1) 2ab+a^2/2b * 2b/2a^2+a
2) (x^2-y^2) : (x+2)^2/2x
3) 2m^2 -18/m * 2m/m+3 + 36m/m-3
4)(y/x - 2 + x/y) * x^2/x^2-y^2
5)(25/a^3-25a + 1/a+5) : (a-5/a^2+5a - a/25+5a)
Answers & Comments
2) (x²-2²):(x+2)²/2x=((x-2)(x+2))*2x/(x+2)²=(x-2)*2x/(x+2)=
=(2x²-4x)/(x+2)=2x(x-2)/(x+2)
3) 2m²-18/m*2m/m+3+36m/m-3=2m²-36/m+36
4) (y/x-2+x/y)*x²/(x²-y²)=(y²-2xy+x²)*x²/((x-y)(x+y))=(y-x)²*x²/((x-y)(x+y)=
=-(y-x)²*x²/((y-x)(x+y)=-x²(y-x)/(x+y)
5) (25/(a³-25a)+1/(a+5)):((a-5)/(a²+5a)-a/(25+5a))=
=(25/(a(a²-5²))+1/(a+5)):((a-5)/(a(a+5))-a/(5(5+a))=
=(25+a(a-5))/(a(a²-5²)):((a-5)*5-a²/(5a(5+a))=
=(25+a²-5a))/(a(a²-5²))*(5a(5+a)/(5a-25-a²))=-(5a(5+a)/(a(a-5)(a+5))=5/(a-5)