Question

Решить систему уравнений

Answer 1

Объяснение:

$y = 7 + x$

${x}^{2} + {y}^{2} = 85$

${x}^{2} + {(7 + x)}^{2} = 85$

${x}^{2} + 49 + 14x + {x}^{2} - 85 = 0$

$2 {x}^{2} + 14x - 36 = 0 \div 2$

${x}^{2} + 7x - 18 = 0$

$d = {b}^{2} - 4ac = 49 + 72 = 121 = {11}^{2}$

$x1 = \frac{ - b - \sqrt{d} }{2a} = \frac{ - 7 - 11}{2} = \frac{ - 18}{2} = - 9$

$x2 = \frac{ - b + \sqrt{d} }{2a} = \frac{ - 7 + 11}{2} = 2$

$y1 = - 2$

$y2 = 9$

Answer 2

Решение задания прилагаю