Выполните действия с дробями. 1) 9х/(6-5х) +12х/(5х-6); 2) (4х2 -1)/(х2 +2х +1) - 3х2 /(х+1)2 ; 3) (4а-в)/12а2 в + (а-5в)/15ав2 ; 4)(m-3n)/8n(m+n) - (m+3n)/8n(m-n); 5) x2 -x +1 - x2 /(x+1).

1) (9x-12x)/(6-5x)= -3x/(6-5x)
2) (4x^2-1-3x^2)/(x+1)^2=(x^2-1)/(x+1)^2=(x-1)(x+1)/(x+1)^2=(x-1)/(x+1)
3) (4b(4a-b)-5a(a-5b))/60a^2b^2=(16ab-4b^2-5a^2+25ab)/60a^2b^2=(41ab-4b^2-5a^2)/60a^2b^2
4) (m-n)(m-3n)-(m+n)(m+3n))/8n(m-n)(m+n)=(m^2-4mn+3n^2-(m^2+4mn+3n^2)/8n(m^2-n^2)=0
5) (x+1)(x^2-x+1-x^2)/(x+1)=1-x