Question

Solve by elimination:
The perimeter of a rectangular floor is 90 feet. Find the dimensions of the floor if the length is twice the width.

Answer 1

How would you even set it up?

Answer 2

are you still there amtran?

Answer 3

Yes I am.

Answer 4

word problems go better one step at a time. So, first step. what is the formula for the perimeter of a rectangle (because this is a rectangular floor).

Answer 5

2L+2w

Answer 6

right... nice

Answer 7

now, how can we make an equation that states that with the given info in the first sentence?

Answer 8

2l+2w=90?

Answer 9

right, but notice how there is no involvement of area in this problem

Answer 10

yes... 2L+2W=90 is perfect!!

Answer 11

what about the second sentence?

Answer 12

But using elimination, we have to have another equation. Would it be 2l+w=90?

Answer 13

That says 2L not 21 sorry

Answer 14

i understand.. lol that is the way i read it.

Answer 15

Read the second sentence and see if you can come up with another equation to make elimination possible.

Answer 16

brb

Answer 17

2l+2w=90
2L+w=180?
I have a hard time setting them up!

Answer 18

it says in the second sentence that the length is twice the width. how would you write that in equation form?

Answer 19

remember that is means equals

Answer 20

if the length is two times the width, that means that L= ?

Answer 21

why is this so like difficile ?

you know that P=2L +2W
and that 1L=2W
than this is very easy

Answer 22

i was trying to help him get to the answer, not give it to him.

Answer 23

yes ok i understand it so step by step will be very very good .correct

Answer 24

so now amtram, you can see that jhonyy set up the system.

Answer 25

it doesnt matter to me. i just want you to understand how to do this problem and others like it. give it to jhonyy

Answer 26

So you set it up just like that? And solve? Will you plug it all in and see what it comes to be? I have 30 and 15.

Answer 27

that would be correct

Answer 28

Will you draw it out for me?

Answer 29

L=30 and W=15

Answer 30

do you want me to make a drawing or give you a set of instructions?

Answer 31

using the draw feature please.

Answer 32

unfortunately, the draw feature is not working properly for me. but i can give you instructions on how to draw your own picture if you like

Answer 33

thanks

Answer 34

draw a rectangle. it does not have to be perfect.

Answer 35

k

Answer 36

lol.

Answer 37

now label the short sides w and the long sides l.

Answer 38

k

Answer 39

then on the long sides, set the l=2w

Answer 40

k

Answer 41

lol... so then, you add up the lengths of the sides to get the perimeter length and set those lengths equal to 90. back to 2L + 2W=90

Answer 42

this problem is more suited to substitution because L=2w, but you can use elimination here too.

Answer 43

Thanks!

Answer 44

by subtracting 2w from both sides, you get L-2w=0

Answer 45

now you have L-2w=0 and 2L+2w=90

Answer 46

then you can add the two equations together to get 3L=90 or L=30

Answer 47

but how do u get the actual #'s?

Answer 48

when you add two numbers together, you put one number above the other and line them up, right?

Answer 49

yes