Question

Tìm x biết:

\(a,x^3-13x=0\)

\(b,2-25x^2=0\)

\(c,x^2-x+\dfrac{1}{4}=0\)

Answer 1

c, \(\left(x-\dfrac{1}{2}\right)^2=0\)
<=>x-\(\dfrac{1}{2}\)=0
<=> x=\(\dfrac{1}{2}\)

Answer 2

a: =>x(x^2-13)=0

=>\(x\in\left\{0;\sqrt{13};-\sqrt{13}\right\}\)

b: =>25x^2=2

=>x^2=2/25

hay \(x=\pm\dfrac{\sqrt{2}}{5}\)