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1) 27a</span>³<span>b</span>⁶<span>+54a</span>²<span>b</span>⁴<span>c</span>²<span>+36ab</span>²<span>c</span>⁴<span>+8c</span>⁶<span>=(3ab</span>²+2c²)(3ab²+2c²)(3ab²+2c²)<span>
2) x^9y^12+3x^3y^4z^4-3x^6y^8z^2-z^6 =(x</span>³y⁴-z²)(x³y⁴-z²)(x³y⁴-z²)<span>
3) (a-b)(a^2-c^2)-(a-c)(a^2-b^2) =(a-b)(a-c)(a+c)-(a-c)(a-b)(a+b)=(a-b)(a-c)(a+c-a-b)=</span>(a-b)(a-c)(c-b)<span>
4) (x+y)^2-10(x^2-y^2)+25(x-y)^2=(x+y-5(x-y))</span>²=(x+y-5x+5y)²=(6y-4x)²=4(3y-2x)(3y-2x)
5*72*sqrt30 = 360*sqrt30 =. 1971, 80120702
X^2+6xy+9y^2-1=(x+3y)^2-1=(x+3y-1)(x+3y+1)