When you have something multiplied by more than one term in parentheses, you multiply that something (in this case 6) by both terms (x and y).
6x+6y+x+y. Add like-terms. 7x+7y
5+10=15
or 1+1+1+1+1+1+1+1+1+1+1+1+1+1+1
The graph of y =8x goes through the origin (0,0) the graph of Y = 8x-1 is displaced on the negative y -axis and goes through the point (0, -1)
The answer is h! Hope this helps!