X-y=7
x^2+y^2=9-2xy
x^2+2xy+y^2=9
(x+y)^2=9
x-y=7
x+y=3
2x=10
x=5
y=-2
x-y=7
x+y=-3
2x=4
x=2
<span>y=-5
</span>
Сtg(2arcctg(-1/√3)=ctg(2*2π/3))=ctg(4π/3)=ctgπ/3=1/√3
Х-3х=-2
-2х=-2
х=-2:-2
х=1
<span>y=x³+2x²-x-2
y=0
</span><span>x³+2x²-x-2=0
</span><span> x³+2x²-x-2</span><u>| x-1</u>
- <u> x³-x²</u> x²+3x+2=(x+1)(x+2)
3x² -x
<u>- 3x² -3x</u>
2x -2
<u> - 2x -2</u>
0
Получаем:
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ОТВЕТ: - 2 ; - 0,5
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