Question

Легчайшие 30 баллов.
Вот скрин

Answer 1

1. а) ((x+y)/x)*x^2/(ax+ay)=(1/x)*x^2/a=x/a
 б) ((a^2-b^2)/b):(a^2+ab)/b=((a-b)(a+b)/b)*b/(a(a+b))=(a-b)/a
в)(-3x^5/y^6)^2=9x^5/y^12
г) ((3a-3c)/a):(a^2-c^2)=3(a-c)/(a(a-c)(a+c))=3/(a(a+c))
2.$( \frac{1}{x-y}- \frac{1}{x+y}) \frac{x^2-y^2}{y^2}= \frac{2y}{x^2-y^2}* \frac{x^2-y^2}{y^2}= \frac{2}{y}$
3.$\frac{a^2-9}{2a+8}* \frac{4a+16}{a^2+6a+9}= \frac{(a-3)(a+3)}{2(a+4)}* \frac{4(a+4)}{(a+3)^2}= \frac{2(a-3)}{a+3}=-0.5$
4.$( \frac{1}{x^2} + \frac{1}{y^2} + \frac{1}{x+y}* \frac{2x+2y}{xy}) \frac{x^2y^2}{x^2-y^2} =( \frac{x^2+y^2}{x^2y^2}+ \frac{2}{xy} ) \frac{x^2y^2}{x^2-y^2} = \frac{(x+y)^2}{x^2y^2} \frac{x^2y^2}{x^2-y^2}$$= \frac{x+y}{x-y}$