SOLUTION: Can someone clarify why in this question 5x is subtracted from 7x and not added?
Does it have anything to do with the miles apart is 1/2 mile-under 1 mph.
Also, is there a way
Algebra.Com
Question 1120731: Can someone clarify why in this question 5x is subtracted from 7x and not added?
Does it have anything to do with the miles apart is 1/2 mile-under 1 mph.
Also, is there a way to know when to add or subtract?
Question
Sally and Lucy are running in the marathon. Sally runs at 7 mph and Lucy runs at 5 mph. If they start at the same time, how long will it be before they are 1/2 mile apart?
7x-5x=1/2
x=1/4 hour; 15 minutes
Thanks in advance.
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
It is because they are going the same direction. Two objects going the same direction separate at a rate equal to the DIFFERENCE of their speeds.
John
My calculator said it, I believe it, that settles it
RELATED QUESTIONS
I have completely forgotten anything that has to do with finding the domain, the range,... (answered by vleith)
Find b2 - 4ac and the number of real solutions to each
equation. -3x2 + 7x = 0... (answered by stanbon,Earlsdon)
A multiple-choice exam has four possible answers for each question. For each correct... (answered by mommacrafton)
True or false: It is not possible to prove one pair of triangles congruent and then use... (answered by KMST)
There was a question about an army travelling 5 mph and a messenger on horseback... (answered by josmiceli,josgarithmetic,ikleyn)
ALAN3354 - please do not respond...I have never received anything but harassment from... (answered by Alan3354)
Can someone please help me with this problem
5x+5y=-7
7x-3y=19
It says to solve the... (answered by Alan3354)
My question is:
Suppose that you did not have a unit circle on the circle, but instead (answered by lwsshak3)
Here is a question that someone asked you and you have already answered it. I do not... (answered by stanbon)