gianarpt
Im so freaking confused and stupid help me
Delete
Share
This Question is Closed
gianarpt
Best Response
You've already chosen the best response.
0
All of the questions are based off of this word problem:
efren leaves home at 9am and walks 4 mph. his bro greg leaves 1/2 hr later and runs 8.5 mph in the same direction as efren. predict the time at which gred will catch up to efren
gianarpt
Best Response
You've already chosen the best response.
0
write an expression for the distance of greg's travels per hour let h stand for time in hours!
gianarpt
Best Response
You've already chosen the best response.
0
write an expression for the distance efren travels per hour plus the distance he will have traveled when greg leaves the house
jim_thompson5910
Best Response
You've already chosen the best response.
1
if greg runs at a speed of 8.5 mph and he runs for h hours, how far will he run?
gianarpt
Best Response
You've already chosen the best response.
0
i dont know
gianarpt
Best Response
You've already chosen the best response.
0
im really stupid no joke when it comes to math
jim_thompson5910
Best Response
You've already chosen the best response.
1
you're not stupid, you just need more practice
jim_thompson5910
Best Response
You've already chosen the best response.
1
say he ran for 1 hour
how far would he get?
gianarpt
Best Response
You've already chosen the best response.
0
8.5 miles?
jim_thompson5910
Best Response
You've already chosen the best response.
1
good, in 2 hours he will go ____ miles
gianarpt
Best Response
You've already chosen the best response.
0
17
jim_thompson5910
Best Response
You've already chosen the best response.
1
how did you get that
gianarpt
Best Response
You've already chosen the best response.
0
8.5 x 2
jim_thompson5910
Best Response
You've already chosen the best response.
1
so in 3 hours, he will run 8.5 x 3 = 25.5 miles
so in 4 hours, he will run 8.5 x 4 = 34 miles
....
in general...
if he runs h hours (some unknown amount of hours), then he will run 8.5 x h or just 8.5h miles
jim_thompson5910
Best Response
You've already chosen the best response.
1
so if d = distance traveled, then
d = 8.5h
gianarpt
Best Response
You've already chosen the best response.
0
oh okay so it says write an expression but im confused on how to write one
jim_thompson5910
Best Response
You've already chosen the best response.
1
ok so you'll just write 8.5h
jim_thompson5910
Best Response
You've already chosen the best response.
1
8.5h is the expression
d = 8.5h is the equation
gianarpt
Best Response
You've already chosen the best response.
0
what about the other expression i have to write for efren
jim_thompson5910
Best Response
You've already chosen the best response.
1
keep in mind that greg started 1/2 hour later than efren
jim_thompson5910
Best Response
You've already chosen the best response.
1
so you have to account for that
gianarpt
Best Response
You've already chosen the best response.
0
oh & it says plus the distance he wil he will have traveled when greg leaves
jim_thompson5910
Best Response
You've already chosen the best response.
1
let's assume they both start at the same time (9:30 am)
if efren walks at 4 mph and he does this for h hours, then he will walk a total of 4h miles
gianarpt
Best Response
You've already chosen the best response.
0
so would it be greg leaving at 9:30??
jim_thompson5910
Best Response
You've already chosen the best response.
1
but this isn't the whole story because efren leaves at 9:00 am instead of 9:30 am
so he's got a 1/2 hr head start
gianarpt
Best Response
You've already chosen the best response.
0
okay
gianarpt
Best Response
You've already chosen the best response.
0
but i dont know what the distance formula is either thats one of the questions
jim_thompson5910
Best Response
You've already chosen the best response.
1
so you have to add in the fact that he walked some additional distance in that half hour where he got the head start
if he walked 0.5 hours (1/2 hr) at a speed of 4 mph, then he would have walked 4*0.5 = 2 miles
jim_thompson5910
Best Response
You've already chosen the best response.
1
distance formula:
distance = rate x time
d = r x t
d = rt
jim_thompson5910
Best Response
You've already chosen the best response.
1
rate is known as speed
gianarpt
Best Response
You've already chosen the best response.
0
oh yeah i remember that lol
gianarpt
Best Response
You've already chosen the best response.
0
so he walked 2 miles??
jim_thompson5910
Best Response
You've already chosen the best response.
1
yes in that half hour where he got the head start
jim_thompson5910
Best Response
You've already chosen the best response.
1
so he walked 2 miles in the first half hour
then he walked an additional 4h miles after 9:30 am
jim_thompson5910
Best Response
You've already chosen the best response.
1
in total, efren walked 2+4h or 4h + 2 miles
gianarpt
Best Response
You've already chosen the best response.
0
so what expression would be for efren plus the distance he would of traveled when greg left
jim_thompson5910
Best Response
You've already chosen the best response.
1
4h + 2
jim_thompson5910
Best Response
You've already chosen the best response.
1
4h is the amount he traveled when greg left
2 is the amount he traveled when greg was still at home
gianarpt
Best Response
You've already chosen the best response.
0
oh i see, sorry ive been up all night doing this and im annoyed and fed up :(
jim_thompson5910
Best Response
You've already chosen the best response.
1
thats ok
jim_thompson5910
Best Response
You've already chosen the best response.
1
to find out when the two will meet, you just set the two expressions equal to one another
jim_thompson5910
Best Response
You've already chosen the best response.
1
8.5h = 4h + 2
and solve for h
gianarpt
Best Response
You've already chosen the best response.
0
so the next question is weird it says write an equation setting the distance expressions in steps 3 and 4 equal
jim_thompson5910
Best Response
You've already chosen the best response.
1
yep you want to find out when the two will walk the same distance (ie find out when/where the two will meet)
gianarpt
Best Response
You've already chosen the best response.
0
could you help me figure that out ill try to do most my self
jim_thompson5910
Best Response
You've already chosen the best response.
1
well you see how i got 8.5h = 4h + 2 right?
gianarpt
Best Response
You've already chosen the best response.
0
yup!
gianarpt
Best Response
You've already chosen the best response.
0
you added the time he waited to the expression
jim_thompson5910
Best Response
You've already chosen the best response.
1
ok great, subtract 4h from both sides
8.5h = 4h + 2
8.5h - 4h = 2
4.5h = 2
what's next?
gianarpt
Best Response
You've already chosen the best response.
0
4.5 = 2 - 2 ?
jim_thompson5910
Best Response
You've already chosen the best response.
1
4.5h is the same as 4.5 x h
jim_thompson5910
Best Response
You've already chosen the best response.
1
how do you undo multiplication
gianarpt
Best Response
You've already chosen the best response.
0
OH! :) I know!!
4.5h/4.5 2/4.5
gianarpt
Best Response
You've already chosen the best response.
0
you divide 2 by 4.5
gianarpt
Best Response
You've already chosen the best response.
0
am i right?
jim_thompson5910
Best Response
You've already chosen the best response.
1
you are correct
jim_thompson5910
Best Response
You've already chosen the best response.
1
so h = ??
jim_thompson5910
Best Response
You've already chosen the best response.
1
2/4.5 = ?
gianarpt
Best Response
You've already chosen the best response.
0
h = 0.4 repeating (so line over the 4)
jim_thompson5910
Best Response
You've already chosen the best response.
1
so that's the rough approximation of how many hours it will take (after 9:30) for the two to meet
jim_thompson5910
Best Response
You've already chosen the best response.
1
and for the two to travel the same distance
jim_thompson5910
Best Response
You've already chosen the best response.
1
convert to minutes to get:
0.444*60 = 26.64
so it will take about 26.64 minutes
gianarpt
Best Response
You've already chosen the best response.
0
thank you very much for helping me i wish i was as smart as you i struggle just to keep my B- average
jim_thompson5910
Best Response
You've already chosen the best response.
1
I'm sure you'll do fine, just keep your head up and keep practicing
gianarpt
Best Response
You've already chosen the best response.
0
thank you jim have a nice day!
jim_thompson5910
Best Response
You've already chosen the best response.
1
you're welcome
jim_thompson5910
Best Response
You've already chosen the best response.
1
you too