Question

[Đoàn Phương Linh]

Tìm x biết

1) \(\left|\dfrac{1}{4}\times x^2+\dfrac{1}{45}\right|+\dfrac{1}{5}=\dfrac{1}{4}\)

2) \(\left(x^2-3\right)\times x^2-2\times x\times\left(x^2-3\right)\)

Answer 1

[Nguyễn Lê Phước Thịnh]

1: =>|1/4x^2+1/45|=1/20

=>1/4x^2+1/45=1/20 hoặc 1/4x^2+1/45=-1/20

=>1/4x^2=1/36

=>x^2=1/36:1/4=1/9

=>x=1/3 hoặc x=-1/3

2: =(x^2-3)(x^2-2x)

=x(x-2)(x^2-3)