Question

Из котлована нужно вывезти 1200т земли. Работают 5 семитонных и 4 пятитонных самосвала. Каждая машина сделала 15 рейсов. Закончена ли вся работа? Если нет сколько земли осталось вывезти? Решите задачу алгебраическим способом (то есть уравнение) Пж Очень надо.

Answer 1

(5+4)15=135т -вывезли за 15 рейсов
1200-135=1065т - осталось вывезти
обязательно уравнением ,если да ,то щас еще подумаю

Answer 2

To solve this problem algebraically, we can set up an equation to represent the total amount of earth that needs to be removed and the total amount of earth that has been removed.

Let's denote the amount of earth that needs to be removed as E and the amount of earth that has been removed as R.

According to the problem, the total amount of earth that needs to be removed is 1200 tons. Therefore, we can write the equation:

E = 1200

Now, let's consider the amount of earth that has been removed. We are given that there are 5 semitonnage dump trucks and 4 fiveton dump trucks, and each truck has made 15 trips.

The amount of earth removed by each semitonnage dump truck is 0.5 tons per trip, and the amount of earth removed by each fiveton dump truck is 1 ton per trip. Therefore, the total amount of earth removed by the semitonnage dump trucks is:

5 trucks * 15 trips/truck * 0.5 tons/trip = 37.5 tons

And the total amount of earth removed by the fiveton dump trucks is:

4 trucks * 15 trips/truck * 1 ton/trip = 60 tons

So, the total amount of earth removed is:

R = 37.5 + 60 = 97.5 tons

Now, we can determine if the work is finished by comparing the amount of earth that has been removed (R) to the amount of earth that needs to be removed (E).

If R is equal to E, then the work is finished. If R is less than E, then there is still earth left to be removed.

Let's substitute the values of E and R into the equation:

1200 = 97.5

Since 97.5 is less than 1200, we can conclude that the work is not finished. There is still earth left to be removed.

To find out how much earth is left to be removed, we can subtract the amount of earth that has been removed (R) from the total amount of earth that needs to be removed (E):

E - R = 1200 - 97.5 = 1102.5 tons

Therefore, there are still 1102.5 tons of earth left to be removed from the excavation site.

I hope this helps! Let me know if you have any further questions.