First graph on first picture is correct because you do up divided by across up was 6 and across was 8 and the line is going down so it’s minus and it goes through 5 on the y axis
It would be 4 months because with extreme fitness 10x4=40 then 40+50=90 then for ultimate fitness 15x4=60 then 60+30=90 so I took 4 months for both memberships to be the same
