Question

Решите уравнения 4x2-9=0 25x2-16=0 81x2+4=0

Answer 1

4x^2-9=0
4x^2=9
x^2=9/4
x=±3/2

25x^2-16=0
25x^2=16
x^2=25/16
x=±5/4

81x^2+4=0
81x^2=-4
$x^2= \frac{-4}{81} \\ \\ x= \sqrt{ \frac{-4}{81} } = {\frac{2i}{9} } \\ \\ x=± \frac{2i}{9}$