Question

срочно даю баллы много​

Answer 1

Ответ:

1) x = -0,625

2) x = 0,5

3) x = -3,5

4) x = +-10

5) -1 и 5 / 6

6) [ -5 ; -0,3 ]

7) x < 12

Объяснение:

1) 0,6x = -3 / 8

x = ( -3 / 8 ) : 0,6  

x = ( -3 / 8 ) : 6 / 10  

x = ( -3 / 8 ) : 3 / 5  

x = ( -3 / 8 ) * 5 / 3  

x = -5 / 8  

x = -0,625

2) 4x - 1 = 2x

4x - 2x = 1

2x = 1

2x ( :2 ) = 1 : 2

x = 0,5

3) 5 + 3 ( x - 4 ) = 5x

5 + 3x - 12 = 5x

3x - 5x = 12 - 5

-2x = 7

-2x : ( -2 ) = 7 : ( -2 )

x = 3,5

4) x^2 - 100 = 0

x^2 = √100

x = +-10

5) 6x^2 + x -5 = 0

D = b^2 - 4ac = 0

1^2 - 4 * 6 ( -5 ) = 1 + 120 = 121 ( 121 > 0, значит 2 корня )

x1 = ( - 1 - √121 ) / ( 2 * 6 ) = ( -1 - 11 ) / 12 = - 12 / 12 = - 1

x2 = ( -1 + √121 ) / ( 2 * 6 ) = ( -1 + 11 ) / 12 = 10 / 12 = 5 / 6

6) | -2x < 10

   | 5x > -1,5

    | -2x : ( -2 ) < 10 : ( -2 )

    | 5x ( :5 ) > -1,5 : 5

     | x > -5

     | x > -0,3

[ -5; -0,3 ]

7) -8 ( x - 2 ) > 4 - 7x

-8x + 16 > 4 - 7x

-8x + 7x > 4 - 16

-x > -12

-x : ( -1 ) > -12 : ( -1 )

x < 12