Решить уравнения: 1. 3x2-1=0
2. 2х2-6х=0
3. 8х2=0
4. х2+81=0
5. х2-=0
6. х2=5х
7. х2+х-3=х+6
8. х2=8,1

VikaSh86 VikaSh86    2   31.01.2021 17:51    1

Ответы
sauleshka3 sauleshka3  02.03.2021 17:52

1.

3 {x}^{2} - 1 = 0 \\ {x}^{2} = \frac{1}{3} \\ x1 = \sqrt{ \frac{1}{3} } = \frac{ \sqrt{3} }{3} \\ x2 = - \frac{ \sqrt{3} }{3}

2.

2 {x}^{2} - 6x = 0 \\ 2x(x - 3) = 0 \\ \\ 2x = 0 \\ x1 = 0 \\ \\ x - 3 = 0 \\ x2 = 3

3.

8 {x}^{2} = 0 \\ {x}^{2} = 0 \\ x 1 = x2= 0

4.

{x}^{2} + 81 = 0 \\ {x}^{2} = - 81

корней нет, так как - 81 < 0.

5.

{x}^{2} = 0 \\ x = 0

6.

{x}^{2} = 5x \\ {x}^{2} - 5x = 0 \\ x(x - 5) = 0 \\ \\ x1 = 0 \\ \\ x - 5 = 0 \\ x2 = 5

7.

{x}^{2} + x - 3 = x + 6 \\ {x}^{2} + x - 3 - x - 6 = 0 \\ {x}^{2} - 9 = 0 \\ {x}^{2} = 9 \\ \\ x1 = 3 \\ x2 = - 3

8.

{x}^{2} = 8.1 \\ \\ x1 = \sqrt{8.1} = \sqrt{81 \times 10} = 9 \sqrt{10} \\ x2 = - 9 \sqrt{10}

ПОКАЗАТЬ ОТВЕТЫ