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mohamed el teir
- 88
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suppose a side of an equation : 26q+1 , and i want the least positive integer value for q that makes this side of equation divisible by 7, is there any short method to do this ?
but when working with higher mod like mod 26 would this way be efficient ? for example when 9x-1 is divisible by 26Merlin3189 said:I don't know any short method, but you can work in mod 7.
So for eg. if 11x + 8 is divisible by 5, then in mod 5
11x + 8 = 0
10x + x + 8 = 0
0 + x + 8 = 0
x + 3 + 5 = 0
x + 3 + 0 = 0
So x is 2, 7, 12, etc.
Ed: just noticed this is too simple. So 13x +9 is divisible by 5. In mod 5,
13x + 9 = 0
3x + 4 = 0
3x = -4
3x = 1
so 3x = 6, 11, 16, 21, 26, 31, 36, etc
so x= 2, 7, 12, etc.
But what method did you use in Excel?Svein said:A short trip into Excel gave q=4 (next one is 11, then 18 , 25).
The short method for computing involves using a simplified approach to solve a problem or equation. It is often a faster and more efficient method compared to traditional methods.
The short method for computing can be used in various situations, but it is most commonly used for complex calculations or when time is limited. It is also useful for checking answers obtained through other methods.
Learning the short method for computing involves understanding the basic principles and concepts behind the method and practicing it through various problems and equations. There are also many online resources and tutorials available for learning the method.
Yes, the short method for computing follows the same principles and formulas as traditional methods, so it will always give accurate results as long as the steps are followed correctly.
One possible disadvantage of the short method for computing is that it may not work for every type of problem or equation. It is important to understand when it is appropriate to use the short method and when other methods may be more suitable.