# Maths problem

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#### gary1

##### Guest
I'm really stuck on this question, and would be incredibly grateful if anyone could help me:

^ = the square root

^5 + y = a rational number (ie a number which can be written as a/b)

can anybody find a value for y?

#### MikeNewYork

##### VIP Member
gary1 said:
I'm really stuck on this question, and would be incredibly grateful if anyone could help me:

^ = the square root

^5 + y = a rational number (ie a number which can be written as a/b)

can anybody find a value for y?

I'm not sure what you are asking. The value of "y" could be just about anything.

A

#### artax

##### Guest
[Summing a rational number to an irrational one you always obtain
an irrational number. So the only way y is rational is that a is equal to b or an his multiple. for example ^5 or 2*^5

#### MikeNewYork

##### VIP Member
artax said:
[Summing a rational number to an irrational one you always obtain
an irrational number. So the only way y is rational is that a is equal to b or an his multiple. for example ^5 or 2*^5

Erm...OK. :wink:

#### Tdol

##### Editor, UsingEnglish.com
Staff member
I was going to say that. <liar> :lol:

H

#### Hong Kong Chinese

##### Guest
Teacher Tdol,

You are correct! She/he is a liar!
One cannot solve an equation with two unknowns!
e.g. a + b = 10

if a is equal one, b will be equal to nine,
However, if a is equal to two, b will be equal to eight and so on.
In conclusion, a and b are variables.

#### RonBee

##### Moderator
Hong Kong Chinese said:
Teacher Tdol,

You are correct! She/he is a liar!
One cannot solve an equation with two unknowns!
e.g. a + b = 10

if a is equal one, b will be equal to nine,
However, if a is equal to two, b will be equal to eight and so on.
In conclusion, a and b are variables.

I believe you are right, but I think Tdol was joking by calling himself a liar when he said, "I was going to say that."

:wink:

#### Tdol

##### Editor, UsingEnglish.com
Staff member
Hong Kong Chinese said:
Teacher Tdol,

You are correct! She/he is a liar!
One cannot solve an equation with two unknowns!
e.g. a + b = 10

if a is equal one, b will be equal to nine,
However, if a is equal to two, b will be equal to eight and so on.
In conclusion, a and b are variables.

Thanks for that, but I was calling myself a liar. If I was right, it was only by accident. If I disagreed with someone's view on the forum,I would try to phrase it more diplomatically. ;-)

#### MikeNewYork

##### VIP Member
tdol said:
Thanks for that, but I was calling myself a liar. If I was right, it was only by accident. If I disagreed with someone's view on the forum,I would try to phrase it more diplomatically. ;-)

I can attest to that fact. :wink:

#### Casiopea

##### VIP Member
Hong Kong Chinese said:
Teacher Tdol,

You are correct! She/he is a liar!
One cannot solve an equation with two unknowns!
e.g. a + b = 10

if a is equal one, b will be equal to nine,
However, if a is equal to two, b will be equal to eight and so on.
In conclusion, a and b are variables.

artax is correct.

artax said:
Summing a rational number to an irrational one you always obtain an irrational number. So the only way y is rational is that a (of a/b, 'a' over 'b') is equal to b or an his multiple. for example ^5 or 2*^5

H

#### Hong Kong Chinese

##### Guest
misunderstanding

I think that I have misunderstood the first reply of Teacher Tdol, which may probably be caused by our culture difference.

Though I almost forgot all the algebra formulas, as a rule, I still insist that:

One unknown in one equation
Two unknowns in two equations
Three unknowns in three equations

Those unknowns can be solved!

I normally don’t call myself a liar, but sometimes an imbecile.

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