Story Problem

Question

A company can make 11 airplane engines for $60,000 while 24 airplane engines cost $67,930. Find a linear equation that models the cost to produce x airplane engines.

Answer 1

change in y = 7930 (67930 - 60000)

change in x = 13 (24 - 11)

m = 610

 

y = 610x + b

Substitute (11, 6000) to determine b.

Answer 2

we have two points: (11, 60000), (24, 67930)

 

Slope: m = (67930-60000)/(24-11) = 7930/13 = 610

 

y = mx + b

y = 610x + b

Use one of the points as (x,y) to find b

60000 = 610(11) + b

 

b = 60000 - 610(11) = 53290

 

y = 610x + 53290

You can check by plugging in the two points to verify