Question

1.решите уравнение :а)4х+7=3(х-1) б)3(х-1)+4(х+1)=6(х+2) в)3(х-1,1)+4(1,2х+2)=7,3х+0,7 2. при каком значении переменной B значение выражения 4 + 5 больше значения выражения B + 2 на 6

Answer 1

$4x + 7 = 3(x - 1) \\ 4x + 7 = 3x - 3 \\ 4 x - 3x = - 3 - 7 \\ 1x = - 10 \\ x = - 10 \div 1 = \\ x = - 10 \\ x = 10$

Answer 2

a) 4x + 7 = 3(x - 1)

4x + 7 = 3x - 3 (Distribute the 3 on the right side)

4x - 3x = -3 - 7 (Bring the x terms to one side and the constants to the other)

x = -10

Therefore, the solution to the equation 4x + 7 = 3(x - 1) is x = -10.

b) 3(x - 1) + 4(x + 1) = 6(x + 2)

3x - 3 + 4x + 4 = 6x + 12 (Distribute the 3, 4 and 6)

7x + 1 = 6x + 12 (Bring the x terms to one side and the constants to the other)

7x - 6x = 12 - 1 (Simplify both sides)

x = 11

Therefore, the solution to the equation 3(x - 1) + 4(x + 1) = 6(x + 2) is x = 11.

c) 3(x - 1.1) + 4(1.2x + 2) = 7.3x + 0.7

3x - 3.3 + 4.2x + 8 = 7.3x + 0.7 (Distribute the 3, 4 and 7.3)

3x + 4.2x - 7.3x = 0.7 - 8 + 3.3 - 4.8 (Bring the x terms to one side and the constants to the other)

-0.1x = -8.3

x = 83

Therefore, the solution to the equation 3(x - 1.1) + 4(1.2x + 2) = 7.3x + 0.7 is x = 83.

Let B be the value at which the expression 4 + 5 is greater than the expression B + 2 by 6.

Then we have:

4 + 5 > B + 2 + 6

9 > B + 8

B < 1

Therefore, the value of B should be less than 1 for the expression 4 + 5 to be greater than the expression B + 2 by 6.