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Nanny needing help with Maths question

(11 Posts)
ClaygateNanny123 Fri 19-Aug-16 13:57:19

This is probably not the best place to post but could anyone help me work out x/4 = 49/x. I know the answer but not how to work out

OP’s posts: |
Ninjapie Fri 19-Aug-16 14:05:15

If you rearrange you get x squared = 49/4
Take square root
X=7/2
Or x=3.5

ClaygateNanny123 Fri 19-Aug-16 16:10:38

Thank you and sorry to be a pain it would you mind talking me through the rearranging

OP’s posts: |
LemonRedwood Fri 19-Aug-16 16:14:10

Isn't it x squared = 49*4?

thecapitalsunited Fri 19-Aug-16 16:15:11

Times both sides to get
(x^2)/4=49
Then times both sides by 4
x^2=49*4
Here is where you can be clever and realise that both are square numbers and we can get to
x=7*2=14

thecapitalsunited Fri 19-Aug-16 16:16:18

Because 49*4=7*7*2*2=(7*2)^2

LemonRedwood Fri 19-Aug-16 16:19:14

Clay When you move a term to the other side of the equals sign, you do the opposite operation, as you are "undoing" that thing to both sides to maintain the equality.

You want all the xs on one side and all the numbers on the other. So, move the /4 to the other side and thus becomes x=49/x * 4. Then move the /x so you get x*x=49*4.
x*x=196 so x=14

dementedpixie Fri 19-Aug-16 16:25:34

I get x (squared) = 49x4 so x = square root of 196 so x= 14

dementedpixie Fri 19-Aug-16 16:33:54

This is how I would do it

ClaygateNanny123 Fri 19-Aug-16 17:37:09

Thank you everyone I understand now - have done it over 20 years ago but forgotten

OP’s posts: |
ReturnfromtheStars Fri 19-Aug-16 21:33:12

Don't forget that it can also be -14, as there are two solutions for the square root of 196: 14 and -14.

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