Answer:
A) For the slope;
Rate of change in profit per change in number of cars washed = 10
B) when he had not washed any car, he was in debt of of $35
C) When he made $255, he had washed 29 cars
Step-by-step explanation:
Slope intercept equation of a line is;
y = mx + c
you made $65 washing ten
cars. Thus, x = 10 and y = 65
So, 65 = 10m + c - - - - (eq 1)
Then after fifteen cars, you made $115.
Thus, x = 15 and y = 115
So; 115 = 15m + c - - - - (eq 2)
Subtract equation 1 from eq(2) to get;
115 - 65 = 15m - 10m + c - c
50 = 5m
m = 50/5
m = 10
Putting 10 for m in eq 1 gives;
65 = 10(10) + c
65 = 100 + c
c = 65 - 100
c = -35
A) Since the slope is m = 10 and slope is m = Δy/Δx, it means that;
Rate of change in profit per change in number of cars washed = 10
B) c = -35 is the y-intercept.
This means when x = 0, y = - 35.
It implies that when he had not washed any car, he was in debt of of $35
C) since we have the slope and intercept, equation is;
y = 10x - 35
If he has made $255,then we have;
255 = 10x - 35
255 + 35 = 10x
290 = 10x
x = 290/10
x = 29 cars washed.
