Answer:
100 miles
Step-by-step explanation:
Let
x ----> the number of miles driven
y ---> the total cost
we know that
The linear equation in slope intercept form is equal to
where
m is the slope or unit rate of the linear equation
b is the y-intercept or initial value
In this problem we have
<em>First Plan</em>
The slope is equal to
The y-intercept is
so
The linear equation is
-----> equation A
<em>Second Plan</em>
The slope is equal to
The y-intercept is
so
The linear equation is
-----> equation B
To find out for what amount of driving do the two plans cost the same, equate equation A and equation B
solve for x
Find the cost
for x=100 miles
substitute in equation A or equation B (the cost is the same)