Linear Equation Word Problems

Question

A meteorologist estimates that on a sunny day, the air temperature decreases by about 4 degrees fahreheit every 1,000 (ft) of elevation gain. On a certain day, the air temperature outside an airplane flying above Seattle is -58 degrees Fahrenheit and the ground level temperature in Seattle is 70 degrees fahrenheit. If x is the height above Seattle, in feet, at which the plane is flying, which of the following best models the situation?

Answer Choices:

A. 70=−4/1,000​x−58

B. 70=4/1,000​x−58

C. −58=−4x+70

D.−58=4x+70

Answer 1

This is a linear equation. The slope of the line is -4/1000, with the ground temperature, x=0, of 70 degrees.

-58 = (-4/1000) x +70

or rearranging

70 = (4/1000)x -58 which is answer B.