Question

Решите уравнения 3х²-21=0

Answer 1

3х^2=21
х^2=7
х=+- корень из 7

Answer 2

$3x^2-21=0\\ \\ 3x^2 = 21 \\ \\ x^2 = 21:3 \\ \\ x^2 = 7 \\ \\ x = б\sqrt{7}; \\ \\ \\ \boxed{\boldsymbol{OTBET: б\sqrt{7}}}$

Answer 3

I can help you solve equations and other math problems. To solve the equation 3x^2-21=0, we need to find the values of x that make the equation true. We can do this by following these steps:

1. Add 21 to both sides of the equation: 3x^2=21 2. Divide both sides by 3: x^2=7 3. Take the square root of both sides: x=±√7 4. Simplify the answer: x≈±2.646

Therefore, the equation has two solutions: x≈2.646 or x≈-2.646. You can check these solutions by plugging them back into the original equation and verifying that they make it true.

If you need more help with solving equations, you can use online calculators like [Symbolab](https://ru.symbolab.com/solver/equation-calculator) or [Mathway](https://www.mathway.com/ru/Algebra). They can show you the steps and explanations for different types of equations. You can also find examples and tutorials on various math topics on websites like [Kontrolnaya-rabota](https://www.kontrolnaya-rabota.ru/s/equal-one/any-uravnenie/e/3x2_minus_2x_ravno_nol/). I hope this was helpful. Have a nice day!