X^2 - 4x + 4 = x^2 - 6x + 9
x^2 - 4x - x^2 + 6x = 9 - 4
- 4x + 6x = 5
2x = 5
x = 2,5
Х-4(9-х)=3х+2
Х-36+4Х=3Х+2
Х+4Х-3Х=2+36
2Х=38
х=19
Ответ:19
X^2 + y^2 = 612
5x = - 20y
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x = - 4y
16y^2 + y^2 = 612
17y^2 = 612
y^2 = 36
y1 = 6
y2 = - 6
x = - 4y
x1 = - 4*6 = - 24
x2 = - 4*( - 6 ) = 24
Ответ ( - 24 ; 6 ) ; ( 24 ; - 6 )