Question

1)Упростите выражение: 2/7*(1,4а-3(1/2в)-1,2*(5/6а-0,5в) 2) Решите уравнение: 0,6*( х +7)-0,5*( х -3)=6,8 3)Купили 0,8 кг. колбасы и 0,3 кг. сыра. За всю покупку заплатили 3,28 тыс. рублей. Известно, что 1 кг. колбасы дешевле 1кг. сыра на 0,3 тыс. рублей. Сколько стоит 1 кг. сыра? СРОЧНОООО!!!!!

Answer 1

2) 0,6х+4,2-0,5х-1,5=6,8

0,1х=-4,2+1,5

0,1х=-2,7

х=-27

Answer 2

Simplifying the Expression: 2/7*(1.4a - 3(1/2v) - 1.2*(5/6a - 0.5v) + 2)

To simplify the expression, let's break it down step by step:

1. Distribute the multiplication: - 2/7 * 1.4a = 2/7 * 1.4 * a = 0.4a - 2/7 * -3(1/2v) = 2/7 * -3 * (1/2) * v = -3/7 * v - 2/7 * -1.2 * (5/6a - 0.5v) = 2/7 * -1.2 * (5/6a) + 2/7 * -1.2 * (-0.5v) = -1/7 * (5/6a) + 2/7 * 0.6v = -5/42a + 6/35v - 2/7 * 2 = 4/7

2. Combine like terms: - 0.4a - 3/7v - 5/42a + 6/35v + 4/7 = (0.4a - 5/42a) + (-3/7v + 6/35v) + 4/7 = 17/42a + 9/35v + 4/7

Therefore, the simplified expression is 17/42a + 9/35v + 4/7.

Solving the Equation: 0.6*(x + 7) - 0.5*(x - 3) = 6.8

To solve the equation, let's follow these steps:

1. Distribute the multiplication: - 0.6 * x + 0.6 * 7 - 0.5 * x + 0.5 * 3 = 6.8 - 0.6x + 4.2 - 0.5x + 1.5 = 6.8

2. Combine like terms: - 0.6x - 0.5x + 4.2 + 1.5 = 6.8 - 0.1x + 5.7 = 6.8

3. Move the constant term to the other side of the equation: - 0.1x = 6.8 - 5.7 - 0.1x = 1.1

4. Solve for x by dividing both sides by 0.1: - x = 1.1 / 0.1 - x = 11

Therefore, the solution to the equation is x = 11.

Finding the Cost of 1 kg of Cheese

To find the cost of 1 kg of cheese, let's use the given information:

1. Let's assume the cost of 1 kg of cheese is C rubles. 2. According to the information given, 1 kg of sausage is 0.3 rubles cheaper than 1 kg of cheese. 3. Therefore, the cost of 1 kg of sausage is (C + 0.3) rubles. 4. The total cost of the purchase is 3.28 thousand rubles, which is equal to 3280 rubles. 5. The total weight of the purchase is 0.8 kg of sausage + 0.3 kg of cheese = 1.1 kg. 6. The cost per kilogram can be calculated by dividing the total cost by the total weight: - C = 3280 rubles / 1.1 kg - C ≈ 2981.82 rubles/kg

Therefore, the cost of 1 kg of cheese is approximately 2981.82 rubles.