1), 2) нет во вложенном файле.
3) [ 6а²/(6-а) ] * [ (а²-36)/3а ] =
= [ - 6а²/(а-6) ] * [ (а-6)(а+6)/3а ]=
= - 2a *(a+6)
4) m²/(m-5) - 25/(m-5) =
= (m² - 25) / (m-5)=
= ( (m-5)(m+5) ) / (m-5)=
= m+5
5) [ (х²+9)/(х+3) ] + [ 6х / (х+3) ] =
= (x²+9+6x) / (x+3) =
= (x²+ 2*3*x +3² ) / (x+3) =
= (x+3)² /(x+3)=
= x+3