Answer:
earnings = $125 + ($50/vacuum)x
Explanation:
This problem is best described by a linear equation whose slope is $50/vacuum and whose y-intercept is $125:
The equation represents the man's total earnings. The independent variable is x, the number of vacuums he sells.
Thus, earnings = $125 + ($50/vacuum)x. As before, the y-intercept is $125 and the slope of the line is ($50/vacuum).
Plot a black dot at (0, $125). Now move 2 units to the right from this dot and from there up by $100 to (2, $225). Plot this new point. Then draw a line through the two points you've plotted.
Table:
x earnings
---- --------------
0 $125
1 $125 + $50 = $175
2 $125 + $100 = $225
and so on.