# Thread: X, Y value problem

1. ## X, Y value problem

Dear Group Members,

Can anyone help me to find out value of X & Y.

X + √y = 21
√x + y = 29

Thanks.

2. Hi.

Originally Posted by yegparkash
Dear Group Members,

Can anyone help me to find out value of X & Y.

X + √y = 21
√x + y = 29
Do you know this method:

Cramer's rule - Wikipedia, the free encyclopedia

?

Yours
Rapha

3. Originally Posted by yegparkash
Dear Group Members,

Can anyone help me to find out value of X & Y.

X + √y = 21
√x + y = 29

Thanks.

Rearrange & square the 2nd equation

$\sqrt{x} + y = 29$
rearranged
$\sqrt{x} = 29 - y$

squared
$x = (29 - y)^2$

replace x in equation
$(29 - y)^2 + \sqrt{y} = 21$

You have 1 equation & 1 unknown

.

NOTE:
The sum of 2 irrational numbers is an irrational number.
For this specific problem, the square root of x & square root of y
must be natural numbers.

4. Originally Posted by Rapha
Hi.

Do you know this method:

Cramer's rule - Wikipedia, the free encyclopedia

?

Yours
Rapha
Cramer's Rule can only be used for a system of linear equations. The posted system is NOT linear.