Ai =7

45? +? 7? =? Fifty two

The analysis is as follows:

This is a two-digit number+one digit = a two-digit number.

Because 4 of 4 delta already represents 40.

And δ of δ 2 represents ten digits, which must be greater than or equal to 4.

Combined with the previous 4△, it can be concluded that △ must be greater than 4.

△ Starting from 5.

When δ= 5

It becomes 45+ um =52.

now

Ai =52-45=7

therefore

△=5

Ai =7

When △ = 6,46+ω = 62, ω= 16 is a two-digit number.