The distributive property tells you the product is found by multiplying each term inside parentheses by the factor outside.
... 4 -6n = 8n +8·7
... 4 = 14n +56 . . . . . . . add 6n to both sides
... -52 = 14n . . . . . . . . . subtract 56 from both sides
... -52/14 = -26/7 = n . . . divide by 14, reduce the fraction
The solution is ...
... n = -26/7 = -3 5/7