(1)(0.5a+3分之1b)平方=(1/4)a^2+ab/3+b^2/9
(2)(-2a平方-7b)平方=(2a^2+7b)^2=4a^4+28a^2b+49b^2
(3)(-8b+4分之1)平方=64b^2-b+1/16
(4) a(b-c)-b(c-a)+c(a-b)=ab-ac-bc+ab+ca-cb=2ab=2*1*2=4
(5)(x-1)(x-2)-3x(x+3)+2(x+2)(x-1)=x^2-3x+2-3x^2-9x+2(x^2+x-2)=-2x^2-12x+2+2x^2+2x-4
=-10x-2=-10/3-2=-16/3
(6)500平方-499乘501=500^2-(500-1)(500+1)=500^2-(500^2-1)=1计算 5a平方b乘(-2ab立方) 4x平方y(3xy平方z-7xz) (2x+3y)(4x+7y) (a+9)(a+1) (4分之3 x-3分之4 y)平方(7)5a平方b乘(-2ab立方) =-10a^3b^4(8)4x平方y(3xy平方z-7xz) =12x^3y^^3z-28x^3yz(9)(2x+3y)(4x+7y) =8x^2+26xy+21y^2(10)(a+9)(a+1) =a^2+10a+9(11)(4分之3 x-3分之4 y)平方=9x^2/16-2xy+16y^2/9