Do you have any tips for the vertical form of supplementary division?

Do you have any tips for the vertical form of supplementary division?

Yes, you have to be very familiar with the multiplication table. I don't mean to memorize it, but you understand the relationship between numbers. This problem is actually very complicated. To put it simply, under what circumstances, 1 will appear, under what circumstances, 2 will appear. Under what circumstances, 9 will appear. And what is the probability of occurrence? You need to study it carefully, Nine Nine Multiplication Table actually contains many things, just like the periodic table of elements

In order to maximize the divisor in the following division formula, what numbers should be filled in each of the two brackets. () 19 = 17 （）
In 8501485014. The 58th place of the decimal part is ()
The number a is 17 times the number B. the product of the two numbers is 31790. The number a is () and the number B is () [write steps]
Add and subtract the same natural number from the numerator and denominator of 9 out of 31, and it becomes 3 out of 5. The natural number is ()
On the same plane, 50 straight lines have at most () intersections [write steps]

1. Let a number be x, then B number be x-17, and the equation x (x-17) = 31790. Use the root formula to solve the equation, and get x = 187, or x = - 170, so a number is 187, B number is 1703. Let this natural number be x, then (31 + X

Mathematical division formula, fill in the appropriate number in brackets to make the formula true!
4、
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（）/ 3 （） 1 （）
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2 8
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（） 6
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The vertical type can be
eight hundred and seventy-nine
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4√ 3516
thirty-two
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thirty-one
twenty-eight
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thirty-six
thirty-six
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0