Year 12s: what will be the first way you research your future options? >>

GCSE equation help!!

solve: 5+4m over 4 = 4-m over 2

Bare with me, I feel really stupid right now because I've forgotten all maths. So far, I've cross multiplied:

4(4-m) = 16-4m
2(5+4m) = 10+8m

10+8m = 16-4m

and I need to get m by itself? Then I've decided to minus the 10 on both sides which would make:

8m = 6-4m

then divide by 4:

2m = 6

and the 4m would be gone? I'm sure too sure what's happened at this point! Can anybody help? I've probably done the whole thing wrong :s-smilie:

would the answer me m = 3 or am I doing it wrong..

(edited 10 years ago)

Reply 1

davros

Original post by ToLiveInADream

solve: 5+4m over 4 = 4-m over 2

would the answer me m = 3 or am I doing it wrong..

you can clear fractions by multiplying both sides by 4.

If you want to check your answer, put m=3 in both sides and see if they are equal - if not, then you have made a mistake :smile:

Reply 2

ToLiveInADream

Original post by davros

you can clear fractions by multiplying both sides by 4.

If you want to check your answer, put m=3 in both sides and see if they are equal - if not, then you have made a mistake :smile:

well m=3 is wrong :frown:

And what do you mean? Can you write it out please?

Reply 3

davros

Original post by ToLiveInADream

well m=3 is wrong :frown:

And what do you mean? Can you write it out please?

Assuming your equation is

\displaystyle \dfrac{5 + 4m}{4} = \dfrac{4 - m}{2}

then multiplying both sides by 4 will give you

5 + 4m = 2(4 - m)

Can you take it from here?

Reply 4

ToLiveInADream

Original post by davros

Assuming your equation is

\displaystyle \dfrac{5 + 4m}{4} = \dfrac{4 - m}{2}

then multiplying both sides by 4 will give you

5 + 4m = 2(4 - m)

Can you take it from here?

That's the equation!

So I multiply it out-

5+4m = 8-2m

Should I minus the five? 4m = 3-2m

Reply 5

EXTREMEninja

Original post by ToLiveInADream

That's the equation!

So I multiply it out-

5+4m = 8-2m

Should I minus the five? 4m = 3-2m

You now need to collect the m terms on one side of the equation. So you should get, 4m+2m = 8-5. I hope you can see what to do from here.

Reply 6

davros

Original post by ToLiveInADream

That's the equation!

So I multiply it out-

5+4m = 8-2m

Should I minus the five? 4m = 3-2m

Right so far...just keep going :smile:

Reply 7

TheHolubowskyj

(5+4m)/4 = (4-m)/2
2(5+4m) = 4(4-m)
(5+4m) = 2(4-m)
5+4m = 8-2m
5+6m = 8
6m = 3

m = 1/2

If you plug it back into the equation it works :smile:

Reply 8

ToLiveInADream

Original post by EXTREMEninja

You now need to collect the m terms on one side of the equation. So you should get, 4m+2m = 8-5. I hope you can see what to do from here.

Woo! Finally.

I got: m=0.5 and checked, it was right!

collect like terms - 6m=3
divide by 6
m=0.5

Reply 9

ToLiveInADream

Original post by davros

Right so far...just keep going :smile:

Thanks for the help :biggrin:

Reply 10

davros

Original post by ToLiveInADream

Thanks for the help :biggrin:

You see, it was completely painless - you really didn't need TSR!!

Reply 11

ToLiveInADream

Original post by davros

You see, it was completely painless - you really didn't need TSR!!

But it was nice for someone to actually go through the steps with me instead of actually just throwing us a random answer from nowhere. Like my new teacher.

Reply 12

davros

Original post by TheHolubowskyj

...
If you plug it back into the equation it works :smile:

Not sure if you've posted in the Maths forum before, but there is a Forum rule that says you should not post full solutions! Most people (like the OP) can get there by themselves with a little nudge in the right direction :smile:

Reply 13

davros

Original post by ToLiveInADream

But it was nice for someone to actually go through the steps with me instead of actually just throwing us a random answer from nowhere. Like my new teacher.