How do i solve this slope of a line from a graph?

Anyone know? will mark brainliest if correct!

Jamie went to home depot.she bought 25 bags of soil that cost $9 per bag.she bought 15 pots at $8 each,and she bought 23 bags of pebbles at $15 each.she used a coupon that gave her $5 off for every 100 dollars she spent.how much did jame pay at the end?

Is there an x intercept in the equation 60*1.15^x