the dependent variable is f(m)...total money earned per day
the independent variable is m...number of miles
f(m) = 3.5m + 65
for 40 miles..
f(40) = 3.5(40) + 65
= 140 + 65
= 205 <== money earned for the day
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the dependent variable is f(p)....total charged
the independent variable is p...the number of pounds
f(p) = 3.5p
for 5 lbs...
f(5) = 3.5(5)
f(5) = 17.50 <== total that was charged