1) x³-x²-9x+9=0
x²(x-1)-9(x-1)=0
(x-1)(x²-9)=0
x=1
x²=9
x=3 x=-3
2)4y³-y²=4y-1
4y³-y²-4y+1=0
y²(4y-1)-(4y-1)=0
(4y-1)(y²-1)=0
4y=1
y=1/4
y²=1
y=1
y=-1
(x+12)²<span>=x(x+8)
x</span>²+24x+144=x²+8x
24x+144=8x
24x-8x=-144
16x=-144
x=-9
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<span>(x-3)(x+1)=(x-2)</span>²
x²+x-3x-3=x²-4x+4
x-3x-3=-4x+4
-2x-3=-4x+4
-2x+4x=4+3
2x=7
x=7/2
x=3.5
3а+3б+с(а+б)=3(а+б)+с(а+б)=(а+б)(3+с)
2(м+н)+км+кн=2(m+n)+k(m+n)=(m+n)(2+k)
by+4(x+y)+bx=4(x+y)+(bx+by)=4(x+y)+b(x+y)=(x+y)(4+b)
a(x-y)+bx-by=a(x-y)+(bx-by)=a(x-y)+b(x-y)=(x-y)(a+b)
3b-3c+a(b-c)=(3b-3c)+a(b-c)=3(b-c)+a(b-c)=(b-c)(3+a)
ab+2(b-d)-ad=2(b-d)+(ab-ad)=2(b-d)+a(b-d)=(b-d)(2+a)
![sinx\leq\frac{\sqrt{2}}{2}\\sinx=\frac{\sqrt{2}}{2}\\x=\left[\begin{array}{cc}\pi/4+2\pi*n\\3\pi/4+2\pi*n\\\end{array}](https://tex.z-dn.net/?f=sinx%5Cleq%5Cfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D%5C%5Csinx%3D%5Cfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D%5C%5Cx%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D%5Cpi%2F4%2B2%5Cpi%2An%5C%5C3%5Cpi%2F4%2B2%5Cpi%2An%5C%5C%5Cend%7Barray%7D)
Отмечаем эти точки на окружности и смотрим когда меньше или равно.
![3\pi/4+2\pi*n\leq x\leq \pi/4+2pi+2pi*n](https://tex.z-dn.net/?f=3%5Cpi%2F4%2B2%5Cpi%2An%5Cleq+x%5Cleq+%5Cpi%2F4%2B2pi%2B2pi%2An)
Ответ: x∈[3π/4+2π*n;9π/4+2π*n], n∈Z.