The Appalachian Trail is about 2,175 miles long. If Katia averages 18 miles each day, how long will it take her to hike the length of the trail?

121 days to hike the length of the trail.

Step-by-step explanation:

Divide 2175 miles by 18 miles/day.  The unit 'miles' will cancel out, leaving with us the unit 'days.'

 2175 miles

= 121 days

  18 mi/day

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions