Answer:
Kathy's speed is equal to [tex]5\ mph[/tex]
Cheryl's speed is equal to [tex]3\ mph[/tex]
Step-by-step explanation:
Let
x-----> Kathy's speed
y----> Cheryl's speed
d----> the distance in miles
t----> the time in hours
s-----> the speed in miles per hour
we know that
The speed is equal to the distance divided by the time
so
[tex]s=d/t[/tex]
solve for the distance d
[tex]d=st[/tex]
In this problem
[tex]x=y+2[/tex] ----> equation A
Kathy's speed
we have
[tex]s=x\ mph[/tex]
[tex]t=4.8\ h[/tex]
substitute in the formula of distance
[tex]d=4.8x[/tex] -----> equation B
substitute equation A in equation B
[tex]d=4.8(y+2)[/tex]
[tex]d=4.8y+9.6[/tex] ------> equation C
Cheryl's speed
we have
[tex]s=y\ mph[/tex]
[tex]t=8\ h[/tex]
substitute in the formula of distance
[tex]d=8y[/tex] -----> equation D
Remember that the distance is the same in both cases
so
equate equation C and equation D and solve for y
[tex]4.8y+9.6=8y[/tex]
[tex]8y-4.8y=9.6[/tex]
[tex]3.2y=9.6[/tex]
[tex]y=3\ mph[/tex]
Find the value of x
[tex]x=y+2[/tex] -----> [tex]x=3+2=5\ mph[/tex]