Josh rides his bike along a 9-mile trail. there are trail markers every 13 mile. the markers start at 13 mile and end at 9 miles. how many markers does josh see on the trail?

So I am assuming you are meaning 1/3 mile instead of 13 mile, I appologise if I am false.

If there is markers every 1/3 mile and the trail is 9 miles, you simply do multiplication, 9x3 = 27, there are 27 markers on the trail

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.