Question 255131
Change banks. Avoid all the math. 
I have several checking accounts with no fees and no minimum balance and I get free checks too. 
a=.11x+7
b=.36x+1
when x=0 a=7
when x=100 a=18
plot and connect the points
when x=0 b=1
when x=100 b=37
plot and connect the points
where they cross is where they charge the same.