Выполните действия: а) 17а^2/26b^2c^3*39b^3c^2/24a^4; б) 4x-y/4x: (16x^2-y^2); в) 3m+1/3m^2-27n^2*3m+9n/2+6m; г) 7y-49.y^2+7y: y-7/y^2+14y+49

А) 17а^2/26b^2c^3*39b^3c^2/24a^4=17b/16a²c
Б) (4x-y)/4x:(16x^2-y^2)=(4x-y)/4x*1/(4x-y)(4x+y)=1/4x(4x+y)
В) (3m+1)/(3m^2-27n^2)*(3m+9n)/(2+6m)=
=(3m+1)/3(m-3n)(m+3n) * 3(m+3n)/2(1+3m)=1/(m-3n)
Г) (7y-49).(y^2+7y):(y-7)/(y^2+14y+49) =
=7(y-7)/y(y+7) * (y+7)²/(y-7)=7(y+7)/y