Решение:![\left \{ {{x² + y² = 20} \atop {y = x - 2}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7Bx%C2%B2+%2B+y%C2%B2+%3D+20%7D+%5Catop+%7By+%3D+x+-+2%7D%7D+%5Cright.+)
![\left \{ {{y = \sqrt{20 - x^{2} } } \atop { y = x - 2 }} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7By+%3D+%5Csqrt%7B20+-+x%5E%7B2%7D+%7D+%7D+%5Catop+%7B%0Ay+%3D+x+-+2+%7D%7D+%5Cright.+)
x - 2 =
![\sqrt{20 - x^{2} }](https://tex.z-dn.net/?f=+%5Csqrt%7B20+-++x%5E%7B2%7D+%7D+)
20 - x² = x² + 4x + 4
16 - 2x² + 4x = 0
x² - 2x - 8 = 0
D₁ = k² - ac = 1 + 8 = 9;
![\sqrt{D1}](https://tex.z-dn.net/?f=+%5Csqrt%7BD1%7D+)
= 3
x₁ = 1 + 3 = 4
y₁ = x - 2 = 2
x₂ = -2
y₂ = -4
Ответ: (4; 2), (-2; -4)
91 5 91
0,091 : 5 = --------- : ---- = --------- *
1000 1 1000
1 91
* ----- = -------- = 0,0182
5 5000
(32-Х)•6-39=45
(32-Х)•6=45+39
(32-Х)•6=84
32-Х=84:6
32-Х=14
Х=32-14
Х=18
Ответ:18
1) 16512
2) 19228
3) 234988
4) 81012
5) 120764
6) 43860
7) 300480
8) 699678
9) 11953904