КОНТРОЛЬНІ РОБОТИ » Кр.6 (9)

Розв’яжіть систему рівнянь x2 – xy = 56, y2 – xy = –7. (x – y)(x + y) = 63. x – y = 7. x2 + y2 – 2xy = 49. (x – y)2 = 49. x2 – y2 = 63. (x – y)(x + y) = 63. x – y = –7. x + y = 9. x – y = 7. x + y = –9. x – y = –7. 2x = 16. x = 8. 2x = –16. x = –8. x = 8. y = 1. x = –8. y = –1. B. (8; 1); (–8; –1).