One rose is 50 cents, so 2 roses cost $1 ( 50 cents x 2).
2 roses per dollar x 20 dollars = 40 total roses sold.
When they sell $20 dollars they make $6, so that means they pay 20-6 = $14 dollars for the 40 roses.
$14 / 40 roses = 0.35 per rose.
She pays 35 cents per rose.
For this case we must find the value of the variable "x" of the following expression:

We apply distributive property to the terms within parentheses: 
We subtract 4x on both sides:

We add 2 to both sides:

We divide between 2 on both sides:

Answer:

* Craig's answer is not reasonable because to add fractions the denominators must be the same.
** Total distance = 5/8 + 1/2 = 5/8 + 4/8 = 9/8 miles
*** Using the line number to prove the answer:
The line number that represents the problem is in the attached figure.
while the distance between 0 and 1 divided to 8 sections
to represent (5/8) count 5 sections from zero ⇒⇒⇒ point (a)
and to represent (1/2) it is the midpoint between 0 and 1 which mean it is 4 sections but it will be counted from point (a) so, adding 4 sections to point (a) the result will be the point (b)
So, counting from 0 to point (b) will give us 9 sections
and while one section represents (1/8)
So the total distance will be 9 * (1/8) = 9/8 which is agree with the result obtained before