Answer:
[tex]2x=54[/tex]
Step-by-step explanation:
We have to find the equation which could be used to solve for Charle's rate if it represented by x and
Let Charle's rate =x
Bill's average rate=9 mph
Relative rate =x-9 mph
Distance traveled by bills after 4 hours=[tex]9\times 4=36 mph[/tex]
Time taken to overtake
[tex]Time=\frac{Distance}{relative rate}[tex]
Substitute the values then we get
[tex]2=\frac{36}{x-9}[/tex]
Using cross multiplication property
Then we get [tex]2(x-9)=36[/tex]
[tex]2x-18=36[/tex]
[tex]2x=36+18[/tex]
[tex]2x=54[/tex]
Hence, option b is true.
