Sixth grade mathematics: the corn planting area in Qinghe township 128 hectares, accounting for 2/5 of the cultivated land in the township. How many hectares of arable land are there in Qinghe Townshi
Sixth grade mathematics: the corn planting area in Qinghe township 128 hectares, accounting for 2/5 of the cultivated land in the township. How many hectares of arable land are there in Qinghe Township?
1, solution: both 128÷2/5.
= 128*5/2
=64*5
=320()
A:
2. Solution: The total length is 120( 1-5/7).
= 120÷2/7
= 120*7/2
=60*7
=420
A: