Question

Алгебра 7 класс В железной руде содержатся железо и примеси в отношении 7:2 .Сколько тонн железа получится из 189 т руды?

Answer 1

1) 189:(7+2)=21т составляет 1 часть руды; 2) 21*7=147 т составляет железо

Answer 2

Просто соотношение 7:2 смотри на это как на целое число 9, раздели 189 на 9 частей,а потом умножь на 7  189/9=21т   21*7=147т

Answer 3

Calculating the Amount of Iron in the Ore

To calculate the amount of iron in the ore, we can use the given ratio of iron to the total ore. The ratio given is 7:2, which means for every 7 parts of iron, there are 2 parts of impurities.

Calculation

To find out how much iron can be obtained from 189 tons of ore, we can use the following calculation:

Step 1: Calculate the total parts in the given ratio: - Total parts = 7 (iron) + 2 (impurities) = 9 parts

Step 2: Calculate the amount of iron in 189 tons of ore: - Amount of iron = (7/9) * 189 tons - Amount of iron = (7/9) * 189 = 147 tons

So, 147 tons of iron can be obtained from 189 tons of the ore.

Conclusion

Based on the given ratio, 147 tons of iron can be obtained from 189 tons of the ore.