Question

PLZ help picture included

Answer 1

Answer:

4 miles

Step-by-step explanation:

Let

x ----> the time to returned back biking in hours

d ---> the distance in miles

s ---> speed in miles per hour

Remember that

The speed or rate is equal to divide the distance by the time

$s=\frac{d}{t}$

The distance is equal to multiply the speed by the time

$d=st$

we know that

$18\ min=\frac{18}{60}\ hours$

The distance to his friend's house and the distance of return is the same

so

$10x=4(x+\frac{18}{60})$

solve for x

$10x=4x+\frac{18}{15}$

subtract 4x both sides

$10x-4x=\frac{18}{15}$

$6x=\frac{18}{15}$

$x=\frac{1}{5}\ hours$

The total distance of the round trip is

$y=10x+4x+\frac{18}{15}$

substitute the value of x

$y=10(\frac{1}{5})+4(\frac{1}{5})+\frac{18}{15}$

$y=2+2=4\ miles$