12⁶ ×(12⁵)² : 12¹⁵ = 12⁶ × 12¹⁰ × 12¹⁵ = 12⁶⁺¹⁰⁻¹⁵ = 12
(x+2)³= x³+6x²+12x+8
(y-2)³= y³-6y²+12y-8
(2x-1)³= 8x³-12x²+6x-1
(3x+1)³= 27x³+27x²+9x+1
x³-3x²+3x-1=x³-3x²
x³-3x²+3x-1-x³+3x²=0
3x-1=0
x= 1/3
x³+3x²+3x+1=x³+3x²+2
x³+3x²+3x+1-x³-3x²-2=0
3x-1=0
x= 1/3
x³+x²+x-x²-x-1-x-x³=0
-1-x=0
x= -1
y³-2y²+4y+2y²-4y+8-y³-2y=0
8-2y=0
y=4
1.(x+1)+x(x+1)=(x+1)·1+x(x+1)=(x+1)(1+x);
2.m²(n+1)+2m(n+1)=(n+1)(m²+2m)=(n+1)m(m+2);
3.x(y-z)+3(z-y)=x(y-z)-3(y-z)=(y-z)(x-3);
4.a(b-c)-b(c-b)
=a(b-c)+b(b-c)
=(b-c)(a+b).