Question

HELP! MEDAL :D
City A and City B had two different temperatures on a particular day. On that day, four times the temperature of City A was 8° C more than 3 times the temperature of City B. The temperature of City A minus twice the temperature of City B was –3° C. What was the temperature of City A and City B on that day?

City A was 5° C, and City B was 4° C.
City A was 3° C, and City B was –1° C.
City A was 8° C, and City B was –3° C.
City A was 5° C, and City B was –5° C.

Answer 1

@ganeshie8 @phi @wio

Answer 2

@dan815 @TheSmartOne @kropot72 @sammixboo @StudyGurl14

Answer 3

So first, we are going to need to come up with equations. The first one, 4 times the temperature of a is going to be written as 4a, okay? and then 8 degrees more than 3 times the temperature of city b is going to be written as 3b+8. Does this make sense to you?

Answer 4

And since that equals 4a, we can finish the first equation by writing 4a=3b+8

Answer 5

Alright

Answer 6

What do you think the second equation is going to be?

Answer 7

For?

Answer 8

For this problem there will be a total of 2 equations. We found the first one and what I need you to do is try to find the other one for "The temperature of City A minus twice the temperature of City B was –3° C"

Answer 9

_-__=-3 is how we will set it up

Answer 10

A - 2b = -2

Answer 11

?

Answer 12

Close. a-2b=-3

Answer 13

My Caps :(

Answer 14

ohh yeah sorry my bad with the -2

Answer 15

lol it's okay :) next, we need to isolate the a in the equation we just came up with by adding 2b to both sides, okay? can you do that really quick?

Answer 16

forgot how to isolate.... could you help me? explain :)

Answer 17

Okay so we have:

a-2b=-3
+2b +2b ----> since we have -2b, we add it to both sides to cancel it on the left side.
-----------
a=2b-3

Answer 18

AHH! lol I get it now

Answer 19

Okay :) great

Answer 20

Now we plug in (2b-3) for a in the first equation, 4a=3b+8

Answer 21

So

4(2b-3)=3b+8

Do you know how to distribute?

Answer 22

4 into 2b and 4 into 3?

Answer 23

yep :)

Answer 24

wait.. you need to add or multiply?

Answer 25

multiply

Answer 26

8b - 12

Answer 27

Ding ding ding! We have a winner! So now that we have

8b-12=3b+8

we need to subtract 3b from both sides to cancel it out on the right side.

8b-12=3b+8
-3b -3b
-------------
5b-12=8

next, we need to add 12 to both sides. Do you want to try it out this time?

Answer 28

17b = 20?

Answer 29

Nope. Close though. You can't add it to 5b because they are not like terms. And when you add them, it just cancels on the side you are removing it from

Answer 30

So it just stays as

5b=20

Answer 31

So what is 20/5?

Answer 32

4

Answer 33

Great! Now we have b=4 because we divided both sides by 5 to isolate the b :)

Answer 34

A?

Answer 35

@haleyelizabeth2017 ? is it A

Answer 36

Lets solve for a first then we will know :)

Answer 37

Alright

Answer 38

Okay, now that we have b, we can plug it in to the equation. We had already isolated a in the second one so lets just plug it into that one :)

a=2b-3

Answer 39

So we do this

a=2(4)-3

Answer 40

What is 2*4? Then what is that minus 3?

Answer 41

5

Answer 42

Ding, ding, ding, we have yet another winner!! :D good job! Now we have finished :) so yes indeed, it is A :D

Answer 43

:D

Answer 44

Do you need help with any more?