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Tilly

Help please with dds algebra

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could any of you maths magicians please help with the following and hopefully explain to me how to come to the answer.

 

Find the inverse of the following functions

 

3x

 

2x +5

 

7(x - 6)

 

x/2 = 7

 

 

Cheers Tilly

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If a function outputs B with A as its input, then the inverse of that function outputs A with B as its input.

 

For example:

 

if f(x)=3x then its inverse is x/3

 

if f(x)=2x+5 then its inverse is (x-5)/2

 

You should be able to do the rest.

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That doesn't make any sense to me at all!!!

 

I am always interested in how people work maths out but I rarely get it! My dad is a genius at maths and used to get so cross with me because I didn't get it when I was at school and now, working at a secondary school I still really struggle with a lot of the concepts (sometimes that helps the kids as if I don't understand I can tell the teacher and it can then be explained in a different way - I remember when I was at school I was made to made to feel so small for putting my hand up and saying I didn't understand - give me English lessons anyday!!!

 

Stella x

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Find the inverse of the following functions

 

3x

 

2x +5

 

7(x - 6)

 

x/2 = 7

As Canopus says - it's asking, "what do you need to do to reverse the result (i.e. get back where you started)"?

 

So the inverse of adding 5 is to take-away 5, the inverse of multiplying by 3 is to divide by 3 etc.

 

When you/son have done them, you can check by putting any number though the function and then working through your inverse and you will get back to the number you started with if it is correct...

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Mumble - that made sense!!!!

Don't sound so shocked!! :lol: :lol: Maths is really logical :thumbs: (Mathematicians on the other hand... :whistle:)

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