Question

решите уравнение:
x²=4
18-x²=2
3x²-27=0
4-9x²=0

Answer 1

$x^{2} = 4; \ x = \pm 2\\18 - x^{2} = 2; \ x^{2} = 16; \ x = \pm 4\\3x^{2} - 27 = 0; \ 3x^{2} = 27; \ x^{2} = 9; \ x = \pm 3\\4 - 9x^{2} = 0; \ 9x^{2} = 4; \ x^{2} = \dfrac{4}{9}; \ x = \pm \dfrac{2}{3}$