Question

3,Giải PT sau

a, 9x²-1=0

b, 3x²=1

c, 7x²=2

d, x²+2019=0

e, x²=3

g, x²=-2

h, x²=0

Answer 1

a, \(x^2=\frac{1}{9}\)

=> \(x=\pm\frac{1}{3}\)

b, \(x^2=\frac{1}{3}\)

=> \(x=\pm\frac{1}{\sqrt{3}}\)

c, \(x^2=\frac{2}{7}\)

=> \(x=\pm\sqrt{\frac{2}{7}}\)

d, Vô nghiệm vì \(x^2+2019\ge2019>0\forall x\)

e, \(x=\pm\sqrt{3}\)

g, Vô nghiệm vì -2 < 0

h, \(x=0\)