so here we solve this , ok !
10(11n+5)= -10n-10+90n
110n+50= -10n+90n-10 ( here in the first part we have multiplied 10 and 11n and 10 and 5 ! in the second we have just arranged the same values together )
110n+50=80n-10 ( here we have just minussed the 10n and 90n as u can see in the 2nd part)
110n-80n=-50-10 (here we have arranged the same values together )
30n=-60 ( here we have minussed in the 1st part and added in the second )
n=-60/30 (divide 60 and 30 gives -2 )
n=-2 So ur answer or n is -2 !