What is the least common denominator of the fraction 3 x over x plus 1 plus the fraction x plus 1 over 2 x plus the fraction 5 over x

3x/(x+1) + (x+1)/(2x) + (5/x)

To find the least common denominator, we multiply the denominators that cannot factor into eachother. x, the denominator in 5/x, fits into 2x, so we do not need to multiply this number.
Therefore, the least common denominator is:
2x(x+1) 

The first term will be multiplied by 2x/2x
The second term will be multiplied by (x+1)/(x+1)
The third term will be multiplied by 2(x+1)

The answer is 225 miles per 4.5 hours. hope this ; )