x2 + y2 = 185, x-y= 3 এর একটি সমাধান হলঃ

x² + y² = 185, x-y= 3 এর একটি সমাধান হলঃ

A (7,4)

B (9,6)

C (2/7)

D (11,8)

Correct Answer: Option D

x-y =3

x = 3 + y

now,

(3+y)2 + y2 = 185

9 + 6y + y2 + y2 = 185

2y2 + 6y - 176 = 0

y2 + 3y - 88 = 0

y2 + 11y - 8y - 88 = 0

y(y +11) - 8(y + 11) = 0

(y + 11)(y - 8) = 0

so,

y = -11 or y = 8

if y = 8, which matches one of the answers of the given options,

x - 8 = 3

x = 3+8 = 11

thus, (11,8)