Martina trains for a marathon. in her first week of training she runs 5 miles. each week after that she increases her run by 0.8 miles. how many weeks of training will it take before she runs more than 36 miles

This process goes with:

5 + 0.8x = 36 ~ Subtract both sides by 5.
0.8x = 31 ~ Divide both sides by 0.8.
x = 38.3 ~ Roughly 38, considering that it doesn't round off to completely covering 36 miles then the answer would be it would take 39 weeks.

39 Weeks.

I hope that helps, have a great rest of your day! ^ ^
~Ghostgate

What do you mean by that?

Graph a should be your answer