Question

please Solve this math

Answer 1

$Given: 2x - \sqrt{7} y = 10$

On Squaring both sides, we get

$(2x - \sqrt{7}y)^2 = (10)^2$

$4x^2 + 7y^2 - 2 * 2x * \sqrt{7}y = 100$

4x^2 + 7y^2 - 2 - 28 = 100

4x^2 + 7y^2 = 100 - 28

4x^2 + 7y^2 = 72.


Hope this helps!

Answer 2

Hey friend,

Here is your answer;
_ _ _ _ _ _ _ _ _ _ _ _ _ _

Given that,

$2x - \sqrt{7}y= 10$

$xy = - \sqrt{7}$
_ _ _ _ _ _ _ _ _ _ _ _ _ _ 

Solution ,

[tex]2x - \sqrt{7}y= 10 [/tex]  (given)

Now, Square on both sides in the above given equation.

$(2x - \sqrt{7}y)^{2} = 10^{2}$

⇒$4 x^{2} +7 y^{2} - (2)(2x)( \sqrt{7} y) = 100$

⇒$4 x^{2} +7 y^{2} - 4 \sqrt{7} xy = 100$  

Now substitute the value of xy in the above equation.

⇒$4 x^{2} +7 y^{2} - 4( \sqrt{7} ) (-\sqrt{7})=100$

⇒$4 x^{2} +7 y^{2} + (4)(7) = 100$

⇒$4 x^{2} +7 y^{2} = 100 - 28$

⇒$4 x^{2} +7 y^{2} = 72$
_____________________________________________________

Hope my answer is helpful to u.