Question

А) 0,9x + 0,47 = 12,8 Б) (12-x)*6,5=23,4 С) (81,8+18,1):(4-0,67)*(0,97+0,28)

Answer 1

Ответ:

0,9x=12,8-0,47

0,9x=12,33

x=12,33÷0,9

x=13,77

12-x=23,4÷6.5

12-x=3,6

-x=3.6-12

x=8.4

А остальное я не знаю

Answer 2

Let's solve each of the given equations:

A) 0.9x + 0.47 = 12.8

To solve this equation, we need to isolate x on one side of the equation. Let's begin:

0.9x = 12.8 - 0.47 0.9x = 12.33

Now, divide both sides of the equation by 0.9 to solve for x:

x = 12.33 / 0.9 x ≈ 13.7

So, the solution to equation A is x ≈ 13.7.

B) (12 - x) * 6.5 = 23.4

Let's solve this equation step by step:

6.5 * (12 - x) = 23.4

Multiply out the left side:

78 - 6.5x = 23.4

Now, subtract 78 from both sides:

-6.5x = 23.4 - 78 -6.5x = -54.6

Divide both sides by -6.5 to solve for x:

x = (-54.6) / (-6.5) x ≈ 8.4

So, the solution to equation B is x ≈ 8.4.

C) (81.8 + 18.1) / (4 - 0.67) * (0.97 + 0.28)

Let's calculate this expression step by step:

(81.8 + 18.1) / (4 - 0.67) * (0.97 + 0.28) = 99.9 / 3.33 * 1.25 = 30.03 * 1.25 = 37.5375

Therefore, the value of the expression is approximately 37.5375.

To summarize: A) x ≈ 13.7 B) x ≈ 8.4 C) ≈ 37.5375