Thread: I really need help - Solveing Equations

1. I really need help - Solveing Equations

Hey,

I am desperatly confused on this homework, we get it online @ MyMaths.co.uk - Bringing Maths Alive

I normally ask my dad, he has a maths degree but he is abroad and he doesn't come back till after I need this homework handed in.

This homework is in Monday, I know you may think it's not urgent now but Im away from Friday-Sunday night so I won't have time, I need to get it done, tonight!

Ok its about solving equations. These are the questions:

4x + 8 = 80 -4x
82-3x=8x -16
2-6x=9 -7x
134-4x=6x +24

6x+11= -101 -8x
-94-8x=8x +18
11-8x=121 -43x
79-6x=12x +23

My sheet says you can use decimals if neccesary

Now I can do questions like this: 6x+32=8x+14. The answer would be x = 9 Is there any realation in that to the ones I can't do in bold?

I'm not asking for the answers, but could someone please explain to me step by step just how to do these questions in bold.

I would be really thankfull

If someone could help me out here, thanks.

2. Originally Posted by Sammy
Hey,

I am desperatly confused on this homework, we get it online @ MyMaths.co.uk - Bringing Maths Alive

I normally ask my dad, he has a maths degree but he is abroad and he doesn't come back till after I need this homework handed in.

This homework is in Monday, I know you may think it's not urgent now but Im away from Friday-Sunday night so I won't have time, I need to get it done, tonight!

Ok its about solving equations. These are the questions:

4x + 8 = 80 -4x
82-3x=8x -16
2-6x=9 -7x
134-4x=6x +24

6x+11= -101 -8x
-94-8x=8x +18
11-8x=121 -43x
79-6x=12x +23

My sheet says you can use decimals if neccesary

Now I can do questions like this: 6x+32=8x+14. The answer would be x = 9 Is there any realation in that to the ones I can't do in bold?

I'm not asking for the answers, but could someone please explain to me step by step just how to do these questions in bold.

I would be really thankfull

If someone could help me out here, thanks.
Anything you do to one side, you must do to the other...

EXAMPLE...

4x + 8 = 80 -4x

8x + 8 = 80

*-8 from both sides*

8x = 72

*divide both sides by 8*

x = 9

3. Originally Posted by Sammy
Hey,

I am desperatly confused on this homework, we get it online @ MyMaths.co.uk - Bringing Maths Alive

I normally ask my dad, he has a maths degree but he is abroad and he doesn't come back till after I need this homework handed in.

This homework is in Monday, I know you may think it's not urgent now but Im away from Friday-Sunday night so I won't have time, I need to get it done, tonight!

Ok its about solving equations. These are the questions:

4x + 8 = 80 -4x
82-3x=8x -16
2-6x=9 -7x
134-4x=6x +24

6x+11= -101 -8x
-94-8x=8x +18
11-8x=121 -43x
79-6x=12x +23

My sheet says you can use decimals if neccesary

Now I can do questions like this: 6x+32=8x+14. The answer would be x = 9 Is there any realation in that to the ones I can't do in bold?

I'm not asking for the answers, but could someone please explain to me step by step just how to do these questions in bold.

I would be really thankfull

If someone could help me out here, thanks.
I'm not sure why you can do the $6x + 32 = 8x + 14$ but not the $4x + 8 = 80 - 4x$. Let's give this one a try.
$4x + 8 = 80 - 4x$

Get all the x's on one side:
$4x + 8 + 4x = 80 - 4x + 4x$

$8x + 8 = 80$

Now get the constants to one side:
$8x + 8 - 8 = 80 - 8$

$8x = 72$

Now get the x by itself:
$\frac{8x}{8} = \frac{72}{8}$

$x = 9$

See if you can do the others. They all follow the same pattern.

-Dan

4. Ok, I tryed it on a different 1.

Q) 6x+11 = -101-8x

6x+11+8x = -101-8x+8x

14x+11=-101

-101-11

= -112

14x=-112

14 x -8 = -112

x = -8.

Is this correct or not? Once again thanks for the explanation.

5. Originally Posted by Sammy
Ok, I tryed it on a different 1.

Q) 6x+11 = -101-8x

6x+11+8x = -101-8x+8x

14x+11=-101

-101-11

= -112

14x=-112

14 x -8 = -112

x = -8.

Is this correct or not? Once again thanks for the explanation.
6x+11 = -101-8x

14x + 11 = -101

*take 11 from both sides*

14x = -112

*divide both sides by 14*

x = -8

So yes, that's correct.