Lời giải:
$(x-1)^3-(x-1)(x^2+x+1)=(x-1)[(x-1)^2-(x^2+x+1)]=(x-1)(x^2-2x+1-x^2-x-1)=(x-1)(-3x)=-3x(x-1)$
Lời giải:
$(x-1)^3-(x-1)(x^2+x+1)=(x-1)[(x-1)^2-(x^2+x+1)]=(x-1)(x^2-2x+1-x^2-x-1)=(x-1)(-3x)=-3x(x-1)$
B1: rut gon bieu thuc
a, (x+y)^2-4(x-y)^2
b, 2(x-y)(x+y)+(x+y)^2+(x-y)^2
B2: tim X
a, (2X-1)^2-4(X+2)^2=9
b, 3(X-1)^2-3X(X-5)=21
B3: Cho bieu thuc
M=(x+3)^3-(x-1)^3+12x(x-1)
a, Rut gon bieu thuc tren
b, Tinh gia tri M tai x=-2/3
c, Tim x de M=16
rut gon bieu thuc :P=5x(x-3)(x+3)-(2x-3)^2+34x(x+2)-5(x+2)^3+25x-1
Rut gon bieu thuc
B=(x+2/x+3)-(5/x^2+x-6)+(1/2-x)
rut gon bieu thuc: 2x2(x-2) - 2x(x-1)(x+1)
rut gon bieu thuc
(2x-1).(x-2)
cho bieu thuc Q=[(x+1/x)^3-(x^6+1/x^6)-2]:[(x+1/x)^3+x^3+1/x^3].rut gon Q va tim min Q
rut gon bieu thuc
(x+1)3+(x-1)3+x3-3x(x+1)(x-1)
cho A= (2x-1)^2 -5x.(x-1)+2.(x+1).(x-2) rut gon bieu thuc A
Cho bieu thuc: ( x-1/ x+1 - x-1/x+1) : 2x / 3x - 3
a, Tim dieu kien xac dinh cua bieu thuc P
b, Rut gon bieu thuc P
c, Tim x thuoc z de P nhan gia tri nguyen.