Question

13*(8n+2)+5*(4-12n)-20+6n*(5-7n)

Answer 1

13*(8n+2)+5*(4-12n)-20+6n*(5-7n)
104n+26+20-60n-20+30n-42n^2=0
-42n^2+74n+26=0
42^2-74n-26=0
a=42. b=-74. c=-26. 
D=−5476-4*42*(-26)=−1108
D<0, корней нет