A Mathematical Olympiad in primary school Fill in the brackets below with seven numbers 0123789 to make it true （）＋（）＝（）－（）＝（） Two of the brackets are two digits

A Mathematical Olympiad in primary school Fill in the brackets below with seven numbers 0123789 to make it true （）＋（）＝（）－（）＝（） Two of the brackets are two digits

1 + 2 = 90-87 = 3 8 + 9 = 20-3 = 17, right_ Thank you. Can you give me the score?

The sum of subtraction and difference is 70, where difference is 4 times of subtraction
(can't use equation)

1. Subtracted = subtracted + difference, i.e. 70 = two subtracted
70 △ 2 = 35 (subtracted or difference + subtracted)
35÷（4+1）×4=28
70 subtraction, subtraction and difference
Subtraction and difference 35
The difference is four times the subtraction
35/5*4=28

For a long time, there has been a ship sailing from Harvard to New York at noon every day, and there is also a ship sailing from New York to Harvard at the same time every day. The time spent by the ship on the way is seven days and nights. How many ships of the same company will come from the opposite side of the ship sailing from Harvard at noon today?

According to the meaning of the question, when a ship leaves, there is a ship entering at the same time, that is, when it leaves the port, it will encounter one ship. If the mileage of each ship is 1 day and night, then the time of meeting the next ship should be 1 △ (1 + 1) = 0.5 (day and night), then 7 × 2 = 14 (ships) can be encountered in seven days and nights