x³-2x²-x+2
5x-6=3x-8
x²-x-6=0
x^4-5x²+4=0
√x-1-x=-7
|3x+1|=4
log2 (x+1)=log3(27)
3^x=9^x+5
Tìm x biết:
(x-2)³-(x-1).(x²+x+1)+6x.(x-1)=5
x(x-2)³-(x-1)(x²+x+1)+6x(x-1): x^4-7x³+18x²-14x+1
x^4-7x³+18x²-14x+1=5
x^4-7x³+18x²-14x+1-5=5-5
x^4-7x³+18x²-14x-4=0
x^4-7x³+18x²-14x-4 : (x-2)(x³-5x²+8x+2)
(x-2)(x³-5x²+8x+2)=0
x-2=0
x=0+2
x=2
x³-5x²+8x+2=0
xấp xỉ -0,21877
Vậy x=2 , x= xấp xỉ -0,21877
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