Question

Если сложить площади трёх озёр - Байкала, Медвежьего озера,и озера Чад, то получится 1/5 часть площали Каспийского моря. Известно, что сумма площадей Байкала и Медвежьего озера - 61 500 км2, сумма площадей Медвежьего озера и озера Чад - 42 700 км 2, сумма площадей Байкала и озера Чад - 44 200км2. Какова площадь каждого озера? Какова площадь Каспийского моря?

Answer 1

1)61500-30000=31500кв.м-Байкал.

2)60000:2=30000кв.м-Медвежье озеро.

3)42700-30000=12700кв.м-Чад.

4)31500+30000+12700=74200кв.м-площадь трёх озёр.

5)74200*5:1=371000кв.м-Каспийское море.

Answer 2

1) 61 500+42 700+44 200=148 400 кв.км - удвоенная сумма площадей озера Байкал, Медвежьего озера и озера Чад

2) 148 400:2=74 200 кв. км - сумма площадей озера Байкал, Медвежьего озера и озера Чад

3) 74 200*5=371 000 кв.км - площадь Каспийского моря

4) 74 200-61 500=12 700 кв.км - площадь озера Чад

5) 42 700-12 700=30 000 кв.км - площадь Медвежьего озера

6) 61 500-30 000=31 500 кв.км - площадь озера Байкал

Answer 3

Calculation of Lake Areas and the Caspian Sea

To find the areas of Lake Baikal, Lake Medvezhye, and Lake Chad, we can set up a system of equations using the given information.

Let's denote the area of Lake Baikal as B, the area of Lake Medvezhye as M, and the area of Lake Chad as C.

From the given information, we have the following equations:

1. The sum of the areas of Lake Baikal and Lake Medvezhye is 61,500 km²: - B + M = 61,500 km²

2. The sum of the areas of Lake Medvezhye and Lake Chad is 42,700 km²: - M + C = 42,700 km²

3. The sum of the areas of Lake Baikal and Lake Chad is 44,200 km²: - B + C = 44,200 km²

We can solve this system of equations to find the individual areas of the lakes.

Solving the System of Equations

To solve the system of equations, we can use substitution or elimination methods. Let's use the elimination method.

By subtracting equation 2 from equation 1, we can eliminate the variable M:

(B + M) - (M + C) = 61,500 km² - 42,700 km²

Simplifying the equation, we get:

B - C = 18,800 km² (Equation 4)

Next, we can add equation 3 to equation 4 to eliminate the variable C:

(B + C) + (B - C) = 44,200 km² + 18,800 km²

Simplifying the equation, we get:

2B = 63,000 km²

Dividing both sides of the equation by 2, we find:

B = 31,500 km²

Now, we can substitute the value of B into equation 4 to find the value of C:

31,500 km² - C = 18,800 km²

Subtracting 18,800 km² from both sides of the equation, we get:

C = 12,700 km²

Finally, we can substitute the values of B and C into equation 1 to find the value of M:

31,500 km² + M = 61,500 km²

Subtracting 31,500 km² from both sides of the equation, we get:

M = 30,000 km²

Calculation Results

Based on the given information and the calculations above, we can determine the areas of the lakes as follows:

- The area of Lake Baikal (B) is 31,500 km². - The area of Lake Medvezhye (M) is 30,000 km². - The area of Lake Chad (C) is 12,700 km².

Area of the Caspian Sea

The area of the Caspian Sea is not directly provided in the given information. However, it is mentioned that the sum of the areas of the three lakes is 1/5 of the area of the Caspian Sea.

Let's denote the area of the Caspian Sea as CS.

From the given information, we have the following equation:

(B + M + C) = (1/5) * CS

Substituting the values of B, M, and C that we found earlier, we get:

31,500 km² + 30,000 km² + 12,700 km² = (1/5) * CS

Simplifying the equation, we find:

74,200 km² = (1/5) * CS

To find the area of the Caspian Sea (CS), we can multiply both sides of the equation by 5:

5 * 74,200 km² = CS

CS = 371,000 km²

Therefore, the approximate area of the Caspian Sea is 371,000 km².

Please note that the calculations provided are based on the given information and assumptions made.