Question

Triangle ABC is congruent to triangle DEF. In triangle ABC, side AB measures 4, side BC measures x+8, and side CA measures 8. In triangle DEF, side DE measures 4, side EF measures 3x+3, and side FD measures 8. What equation would help you to solve for the side length of BC and EF? Explain your reasoning using complete sentences.

Answer 1

@sleepyjess

Answer 2

O_O

Answer 3

Its really annoying isnt it? XD

Answer 4

I hate it :/

Answer 5

Ok,

Answer 6

This is the information we are given.

Answer 7

We know that they are congruent, so x + 8 = 3x + 3

Answer 8

Oke..?

Answer 9

Do you know how to solve for x?

Answer 10

I'm not so sure... can you guide me through?
Do you have to try to leave x alone?

Answer 11

We need to get all x's on one side, and all constants on the other side.

Answer 12

So we start with x + 8 = 3x + 3. Subtract 3 from both sides

Answer 13

That would be x + 5 = x?

Answer 14

Close, good try. We still have 3x on the right side though.

Answer 15

So now we have x + 5 = 3x. Subtract x from both sides :)

Answer 16

5 = 3?

Answer 17

@cwrw238

Answer 18

@Straybullet, can u help by any chance?

Answer 19

Okke so you have to remember that when youre subtracting youre only subtracting a constant, so when you subtract 3 from each side you are subtracting only the 3

Answer 20

going from 3x + 3 to x would mean you hd divided by 3, not subtracted...so in order to subtract you merely take away the 3 and thats it

Answer 21

Sleepyjess explains some... but we stayed at 5 = 3

Answer 22

okke so you have x + 5 = 3x
The same thing applies...youre not actuatlly taking away the x entirely

Answer 23

so on the one side, x - x = what?

Answer 24

Still a bit confused...

Answer 25

Okke thats what im trying to explain so... thing of each part as totally separate

Answer 26

on one side, you have (x) and (+5) and you are 'adding' (-x) the x's cancel each other out so you have just (5) on the one side

Answer 27

Would that then leave 5 = x?

Answer 28

on the other side you have (3x) which is the same as saying that you have (x) (x) (x) or three xs and since you subtracted one x from the other side you only subject one x from this side

Answer 29

Which means if you have: (x) (x) (x) - (x) what will you have?

Answer 30

So, what would I have left?

Answer 31

@sleepyjess, ur back :P

Answer 32

Thats what im asking you, its very easy....you have three xs and you take away one

Answer 33

If you have 3 kittens, and you give away 1 kitten, how many kittens do you have?

Answer 34

2...

Answer 35

Yes, so we have 5 = 2x

Answer 36

so 2x.....
5 = 2x

Answer 37

OOOHHH! I see what's going on now :P

Answer 38

Now, divide each side by 2.

Answer 39

2.5 = x

Answer 40

Yiiisss :E

Answer 41

Yayz!

Answer 42

So, wait, what do I have to write down then?

Answer 43

Just write down the process of going from x + 8 = 3x + 3 to x = 2.5

Answer 44

So now you have to substitute 2.5 for x into one of the original equations

Answer 45

Then do what @Straybullet said, substitute in 2.5

Answer 46

Right how you solved it and then the final step is putting 2.5 as x in one of the equations, (x +8) would be the easier one

Answer 47

I'm confused again... sorry :/

Answer 48

Do you know the steps to get from x + 8 = 3x + 3?

Answer 49

x + 8 = 3x + 3
x + 8 - 3 = 3x + 3 - 3
x + 5 = 3x

Answer 50

Then what?

Answer 51

DIVIDE XD

Answer 52

Subtract

Answer 53

You forgot to give away the kitten

Answer 54

Its subtract again cause you still have to subtract the one x from each side

Answer 55

OHH, okee

Answer 56

After that we get 5 = 2x, then divide

Answer 57

Solving for x:
x + 8 = 3x + 3
x + 8 - 3 = 3x + 3 - 3
x + 5 = 3x
x - x + 5 = 3x - x
5 = 2x

Answer 58

divide by 2, and we get 2.5 = x?

Answer 59

yep

Answer 60

Alright, now what comes next?

Answer 61

Substitute in 2.5 for x

Answer 62

So, Line BC = 10.5, Line EF = 10.5

Answer 63

@sleepyjess, @Straybullet

Answer 64

yes

Answer 65

Yiiss

Answer 66

THis is what I got written so far...

Answer 67

Solving for x:
x + 8 = 3x + 3
x + 8 - 3 = 3x + 3 - 3
x + 5 = 3x
x - x + 5 = 3x - x
5 = 2x
5/2 = 2x/2
2.5 = x

Line BC = 10.5
Line EF = 10.5

Answer 68

Do I have to write something else?

Answer 69

Show the work for getting to 10.g

Answer 70

*10.5

Answer 71

What about these 2?
What equation would help you to solve for the side length of BC and EF? Explain your reasoning using complete sentences.

Answer 72

Is the equation you used in the beginning, the x + 8 = 3x + 3

Answer 73

Yes, i believe so :)

Answer 74

I meant 'its' the equation that would help you to solve for the side length of BC and EF is x + 8 = 3x + 3