Question

Решите уравнение
x2 = 16/25
x2 = 0,04
x2 = 28/343

Answer 1

Объяснение:

$\tt\displaystyle x^{2}=\frac{16}{25}\\\\x_{1;2} =\pm\sqrt{\frac{16}{25}}=\pm\sqrt{\frac{4^{2}}{5^{2}}}=\pm\frac{4}{5}\\\\x_{1}=\frac{4}{5}\\\\x_{2}=-\frac{4}{5}\\\\\\\\x^{2}=0,04\\\\x_{1;2}=\pm\sqrt{0,04}=\pm0,2\\\\x_{1}=0,2\\\\x_{2}=-0,2\\\\\\\\x^{2}=\frac{28}{343}\\\\x_{1;2} =\pm\sqrt{\frac{28}{343}}=\pm\sqrt{\frac{4*7}{49*7}}=\pm\sqrt{\frac{4}{49}}=\pm\sqrt{\frac{2^{2}}{7^{2}}}=\pm\frac{2}{7}\\\\x_{1}=\frac{2}{7}\\\\x_{2}=-\frac{2}{7}$