1.[(m²-2n²)(m²+2n²)]²= [(m²)²-(2n²)²]²= [m^4-4n^4]²= m^8 - 8m^4•n^4 + 16n^82.(a²+ab-3b²)(a²-ab+3b²)= [a²+(ab-3b&su 展开
1.[(m²-2n²)(m²+2n²)]²= [(m²)²-(2n²)²]²= [m^4-4n^4]²= m^8 - 8m^4•n^4 + 16n^82.(a²+ab-3b²)(a²-ab+3b²)= [a²+(ab-3b²)][(a²-(ab-3b²)]= (a²)²-(ab-3b²)²= a^4 - (a²b²- 6ab³+ 9b^4)= a^4 - a²b²+ 6ab³- 9b^43.(a³+27)(a-3)(a²+3a+9) = (a³+27)(a³-3³)= a^6 - 27²= a^6 - 729 4.(x+0.2)(x²-0.2x+0.04)-(x-0.4)(x²+0.4x+0.16)= (x³+0.2³) - (x³-0.4³)= x³+ 0.008 - x³+ 0.064= 0.0725.(x+2)(x²-2x+4)-x(x-1)(x+1)= (x³+2³)-x(x²-1)= x³+ 8 - x³+ x= x + 86.[(a+0.5b)²+(a-0.5b)²]*(2a²-0.5b²) = [(a²+ab+0.25b²)+(a²-ab+0.25b²)]*(2a²-0.5b²)= [2a²+0.5b²]*(2a²-0.5b²)= (2a²)²-(0.5b²)²= 4a^4 - 0.25b^47. 6(x+1)²+2(x-1)(x²+x+1)-2(x+1)³= 32 = 2(x+1)²[3-(x+1)] + 2(x³-1)= 2(x²+2x+1)(2-x) + 2(x³-1)= 2(2x²+4x+2-x³-2x²-1 + x³-1)= 2(4x) = 32--->x=48.(4x-1)²-(2x+1)(8x-9) = 10= (16x²-8x+1)-(16x²-10x-9)= 2x+10 = 10--->x = 09. (3x-2)²>(3x+1)(3x-1)--->9x²-12x+4＞9x²-1--->12x＜5--->x＜5/1210.(x+y+z)²+x²+y²+z²= (x²+y²+z²+2yz+2zx+2xy)+x²+y²+z²= (y²+2yz+z²)+(z²+2zx+x²)+(x²+2xy+y²)= (y+z)²+(z+x)²+(x+y)²11.(m+n+p)²-m²-n²-p²= (m²+n²+p²+2mn+2np+2pm)-m²-n²-p²= 2mn+2np+2pm= (mn+mp)+(np+mn)+(pm+np)= m(n+p)+n(p+m)+p(m+n) 收起
