245

a)
9x^2=4
x^2=\frac{4}{9}
x=\pm\frac{2}{3}
b)
100x^2-4=0
100x^2=4
x^2=\frac{4}{100}
x=\pm\frac{2}{10}
x=\pm\frac{1}{5}
c)
x^2+25=9
x^2=-16
x=\sqrt{-16}
ei voi ratkaista
d)
2x^2-80=0
x^2=40
x=\sqrt{2\cdot2\cdot2\cdot5}
x=\sqrt{4}\sqrt{10}
x=\pm2\sqrt{10}
e)
x^2=100x
x=100
f)
\frac{2}{3}x^2-\frac{3}{2}=0
\frac{2}{3}x^2=\frac{3}{2}
x^2=\frac{2}{3}\cdot\frac{2}{3}
x^2=\frac{4}{9}
x=\pm\frac{2}{3}