The "slope" is the amount added each day. The "intercept" is the initial amount in the bank. If y represents that amount and x represents the number of days money is added, then the slope-intercept equation is ...
y = 3x +20
When x=5, the value is ...
y = 3(5) +20 = 15+20
y = 35 . . . . amount of dollars in the bank after 5 days
The first or third graph represents the situation After 25 days he would expect to have , i would say 88 packs left I cant make out the bottom figure below third graph
