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# 3(2c – 5) – 2(c – 4) watch

1. Can someone explain this to me?
2. Are you missing an equals sign?
3. (Original post by mphysical)
Are you missing an equals sign?
No
4. (Original post by DANIELREED)
Can someone explain this to me?

3(2c - 5) - 2(c - 4)

I'm assuming there is no equal, basically all you do is factorise it, so..

3(2c - 5)
3 x 2c = 6c
3 x -5 = -15

So: 6c - 15
**Don't forget to use the -/+ rule**

Now,
2(c - 4) ** do not use -2 as that isn't to do with equation, if it was --2(2c - 4) that would be different**
Once again, time them.

2 x c = 2c
2 x -4 = -8

2c - 8

Now bring them together...
6c - 15 + 2c - 8

Now deal with them in groups.

6c - 2c = 4c
-15 - 8 = -23.

So answer is... 4c - 23.
5. Thanks alot :d
(Original post by ckfeister)
3(2c - 5) - 2(c - 4)

i'm assuming there is no equal, basically all you do is factorise it, so..

3(2c - 5)
3 x 2c = 6c
3 x -5 = -15

so: 6c - 15
**don't forget to use the -/+ rule**

now,
2(c - 4) ** do not use -2 as that isn't to do with equation, if it was --2(2c - 4) that would be different**
once again, time them.

2 x c = 2c
2 x -4 = -8

2c - 8

now bring them together...
6c - 15 + 2c - 8

now deal with them in groups.

6c + 2c = 8c
-15 - 8 = -23.

So answer is... 8c - 23.
6. (Original post by DANIELREED)
Can someone explain this to me?
Which part are you unsure about, the multiplications or subtractions?
7. (Original post by ckfeister)
3(2c - 5) - 2(c - 4)

Now,
2(c - 4) ** do not use -2 as that isn't to do with equation, if it was --2(2c - 4) that would be different**
Once again, time them..
But it is -2(2c - 4)
8. (Original post by ckfeister)
3(2c - 5) - 2(c - 4)

I'm assuming there is no equal, basically all you do is factorise it, so..

3(2c - 5)
3 x 2c = 6c
3 x -5 = -15

So: 6c - 15
**Don't forget to use the -/+ rule**

Now,
2(c - 4) ** do not use -2 as that isn't to do with equation, if it was --2(2c - 4) that would be different**
Once again, time them.

2 x c = 2c
2 x -4 = -8

2c - 8

Now bring them together...
6c - 15 + 2c - 8

Now deal with them in groups.

6c + 2c = 8c
-15 - 8 = -23.

So answer is... 8c - 23.
Lol you just did his homework

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9. (Original post by DANIELREED)
Can someone explain this to me?
http://www.thestudentroom.co.uk/forumdisplay.php?f=38
10. (Original post by EnemyofState)
Lol you just did his homework

Posted from TSR Mobile
Since when did homework assignments consist of one question?
11. (Original post by mphysical)
But it is -2(2c - 4)
.-.
12. (Original post by EnemyofState)
Lol you just did his homework

Posted from TSR Mobile
(Original post by ScienceFantatic)
Since when did homework assignments consist of one question?
^^
13. (Original post by ckfeister)
3(2c - 5) - 2(c - 4)

I'm assuming there is no equal, basically all you do is factorise it, so..

3(2c - 5)
3 x 2c = 6c
3 x -5 = -15

So: 6c - 15
**Don't forget to use the -/+ rule**

Now,
2(c - 4) ** do not use -2 as that isn't to do with equation, if it was --2(2c - 4) that would be different**
Once again, time them.

2 x c = 2c
2 x -4 = -8

2c - 8

Now bring them together...
6c - 15 + 2c - 8

Now deal with them in groups.

6c + 2c = 8c
-15 - 8 = -23.

So answer is... 8c - 23.
This is incorrect, the answer is 4c-7
14. (Original post by ckfeister)
3(2c - 5) - 2(c - 4)

So answer is... 8c - 23.
No.

1. Expand the brackets by multiplying them by the coefficient (3 and -2, not 2).
2. Collect like terms.
15. .//
16. (Original post by B_9710)
This is incorrect, the answer is 4c-7
Exactly what I got.
17. (Original post by B_9710)
This is incorrect, the answer is 4c-7
(Original post by Federerr)
Exactly what I got.
So did I. As in my earlier post

(Original post by ckfeister)
3(2c - 5) - 2(c - 4)

Now,
2(c - 4) ** do not use -2 as that isn't to do with equation, if it was --2(2c - 4) that would be different**
(Original post by mphysical)
But it is -2(2c - 4)
But ckfeister seems to have lost the plot since.
Seems to think it is OK to ignore the minus sign.
So not only did he do the guy's homework.
He actually did it wrong
18. (Original post by mphysical)
(Original post by B_9710)
This is incorrect, the answer is 4c-7

So did I. As in my earlier post

But ckfeister seems to have lost the plot since.
Seems to think it is OK to ignore the minus sign.
So not only did he do the guy's homework.
He actually did it wrong

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