Question

tìm x biết

b) 3x - x^3=0

c) (x-1).(x-3)=0

d) Ix+1I + Ix+2I+I2x+3I=2016x

Answer 1

b) ta có: x-1 = 0 => x= 0+1 = 1

            x-3 = 0 => x= 0+3 = 3

vậy x =1 và x = 3

Answer 2

b)<=>3x-x³=-x(x²-3)

=>-x(x²-3)=0

Th1:-x=0

Th2:x²-3=0

=>x²=3

=>x=\(\pm\sqrt{3}\)

c)(x-1).(x-3)=0

Th1:x-1=0

=>x=0

Th2:x-3=0

=>x=3

d)Ix+1I + Ix+2I+I2x+3I=2016x

<=>Ix+1I + Ix+2I+I2x+3I=|2x+3|+|x+2|+|x+1|

=>|2x+3|+|x+2|+|x+1|=2016x

=>x\(\approx\)0.00298210735586481

Answer 3

b) x=1

c) x=1;3

d) chịu

Answer 4

ngu dốt