Question

$x {}^{2} + 7y {}^{2} = 17 \\ 7x {}^{2} - y {}^{2} = 17$

Answer 1

x^2 + 7y^2 = 17

7x^2 - y^2 = 17

multiplying equation ( ll ) by 7 we get

49x^2 - 7y^2 = 119

Adding equation ( l ) & ( lll ) we get

50x^2 = 136

x ^2 = 136 /50

x^2 = 68/25

x = root 68 / 5

putting x^2 = 68/25 in equation ( ll ) find y^2

Answer 2

x = √3

y = √2

Verification:-

(√3)² + 7(√2)² = 3 + 14 = 17

7(√3)² - (√4)² = 21 - 4 = 17

-WonderGirl