First, let's find out how much of the land was cleared for planting. The farmer cleared 90% of the total land for planting.

Cleared land = 90% of total land
Cleared land = 0.90 * 6999.999999999999 acres

Now, let's calculate the amount of cleared land that was planted with potato and tomato.

Potato land = 20% of cleared land
Potato land = 0.20 * cleared land

Tomato land = 70% of cleared land
Tomato land = 0.70 * cleared land

The remaining cleared land was planted with corn. So, the corn land is the cleared land minus the potato land and the tomato land.

Corn land = Cleared land - (Potato land + Tomato land)

Let's calculate the cleared land first:

Cleared land = 0.90 * 6999.999999999999
Cleared land = 6299.999999999999 acres (approximately)

Now, let's calculate the potato and tomato land:

Potato land = 0.20 * 6299.999999999999
Potato land = 1259.9999999999998 acres (approximately)

Tomato land = 0.70 * 6299.999999999999
Tomato land = 4409.999999999999 acres (approximately)

Now, let's calculate the corn land:

Corn land = Cleared land - (Potato land + Tomato land)
Corn land = 6299.999999999999 - (1259.9999999999998 + 4409.999999999999)
Corn land = 6299.999999999999 - 5669.999999999999
Corn land = 630 acres (approximately)

So, approximately 630 acres of cleared land were planted with corn.
먼저, 얼마나 많은 땅이 식물을 심기 위해 개간되었는지 알아봅시다. 농부는 총 땅의 90%를 개간했습니다.

개간된 땅 = 전체 땅의 90%
개간된 땅 = 0.90 * 6999.9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999