Question

Даю 100 баллов!!! Решите квадратные уравнения 7x^2+28=0 x^2+2x=0 6x^2-12=0 x^2-2x=0 121-x^2=0 x^2-21=0 Помогите пж, дам лучший!!!

Answer 1

Ответ:

1) нет корней

2) x = 0, x = -2

3) x = $\sqrt{2}$, x = -$\sqrt{2}$

4) x = 0, x = 2

5) x = 11, x = -11

6) x = $\sqrt{21}$, x = -$\sqrt{21}$

Объяснение:

1)

7x^2+28=0

7 * ($x^{2}$ + 4) = 0

$x^{2}$ + 4 = 0

$x^{2}$ = -4

Квадрат не может принимать отрицательные значения, значит уравнение не имеет корней.

2)

x^2+2x=0

х * (х + 2) = 0

x = 0       x = -2

3)

6x^2-12=0

6 * ($x^{2}$ - 2) = 0

$x^{2}$ - 2 = 0

$x^{2}$ = 2

x = $\sqrt{2}$    x = -$\sqrt{2}$

4)

x^2-2x=0

x*(x - 2) = 0

x = 0       x - 2 = 0

              x = 2

5)

121-x^2=0

$x^{2}$ = 121

x = ±$\sqrt{121}$

x = 11        x = -11

6)

x^2-21=0

$x^{2}$ = 21

x = ±$\sqrt{21}$

x = $\sqrt{21}$               x = -$\sqrt{21}$

Answer 2

решение смотри на фото/////////////

Answer 3

Solving Quadratic Equations

Let's solve the given quadratic equations one by one.

1. Equation: 7x^2 + 28 = 0

To solve this equation, we can start by subtracting 28 from both sides of the equation:

7x^2 = -28

Next, we divide both sides of the equation by 7 to isolate x^2:

x^2 = -4

Taking the square root of both sides, we get:

x = ±√(-4)

Since the square root of a negative number is not a real number, this equation has no real solutions.

2. Equation: x^2 + 2x = 0

To solve this equation, we can factor out x:

x(x + 2) = 0

This equation will be true if either x = 0 or x + 2 = 0. Solving for x in each case, we get:

x = 0 or x = -2

So, the solutions to this equation are x = 0 and x = -2.

3. Equation: 6x^2 - 12 = 0

To solve this equation, we can start by adding 12 to both sides of the equation:

6x^2 = 12

Next, we divide both sides of the equation by 6 to isolate x^2:

x^2 = 2

Taking the square root of both sides, we get:

x = ±√2

So, the solutions to this equation are x = √2 and x = -√2.

4. Equation: x^2 - 2x = 0

To solve this equation, we can factor out x:

x(x - 2) = 0

This equation will be true if either x = 0 or x - 2 = 0. Solving for x in each case, we get:

x = 0 or x = 2

So, the solutions to this equation are x = 0 and x = 2.

5. Equation: 121 - x^2 = 0

To solve this equation, we can start by subtracting 121 from both sides of the equation:

-x^2 = -121

Next, we multiply both sides of the equation by -1 to change the sign:

x^2 = 121

Taking the square root of both sides, we get:

x = ±√121

Simplifying, we have:

x = ±11

So, the solutions to this equation are x = 11 and x = -11.

6. Equation: x^2 - 21 = 0

To solve this equation, we can start by adding 21 to both sides of the equation:

x^2 = 21

Taking the square root of both sides, we get:

x = ±√21

So, the solutions to this equation are x = √21 and x = -√21.

I hope this helps! Let me know if you have any further questions.