Question

4x² - 20 = 1580
10x² +50= 2300
8x²= 3200
x² - 6 = 120​

Answer 1

$\bf{4x^{2} - 20 = 1580$

$4x^{2} =1580+20$

$4x^{2} =1600$

$x^{2} =\frac{1600}{4}$

$x^{2} = 400$

$x = \±\sqrt{400}$

$\boxed{\bf{x = \±\sqrt{20}}}$

Ya que  $\bf{20\times 20=400$, entonces la raíz cuadrada de 400 es 20.

$\bf{10x^2 +50= 2300$

$10x^{2} =2300-50$

$10x^{2} =2250$

$x^{2} =\frac{225}{10}$

$x^{2} =225$

$x = \± \sqrt{225}$

$\boxed{\bf{x=\±\sqrt{15}}}$

$\bf{ 8x^{2} = 3200$

$x^{2} = \frac{3200}{8}$

$x^{2} =400$

$x = \± \sqrt{400}$

$\boxed{\bf{x = \± \sqrt{20}}}$

$\bf{x^{2} - 6 = 120$

$x^{2} =120+6$

$x^{2} =126$

$x = \± \sqrt{126}$

$\boxed{\bf{x = \± 3\sqrt{14}}}$