One week, Kerry travels 125 miles and uses 5 gallons of gasoline. The next week, she travels 175 miles and uses 7 gallons of gasoline. Which best describes the function that can be used to represent m, the number of miles traveled, and g, the number of gallons used? direct variation; m = kg direct variation; gm = k inverse variation; inverse variation;

Respuesta :

Answer:

m = kg

Step-by-step explanation:

125 = 5k   , k = 25  where k is the constant of variation.

175 = 7k,  k = 25

Direct variation m = kg

Answer:

[tex]m=kg[/tex]  direct variation

Step-by-step explanation:

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form [tex]y/x=k[/tex] or [tex]y=kx[/tex]

In this problem

Let

m------> the number of miles traveled

g------> the number of gallons used

we have that

[tex]\frac{125}{5}\frac{miles}{gallons}=25\frac{miles}{gallons}[/tex]

[tex]\frac{175}{7}\frac{miles}{gallons}=25\frac{miles}{gallons}[/tex]

The linear direct variation that represent the situation is equal to the equation

[tex]\frac{m}{g}=k[/tex]  or [tex]m=kg[/tex]

where

k is the constant of proportionality

In a direct variation the constant k is equal to the slope m of the line, and the line passes through the origin

[tex]k=25\frac{miles}{gallons}[/tex]

substitute

[tex]m=kg[/tex] -------> [tex]m=25g[/tex]