Question 1092862
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One way to solve it is to reduce to the quadratic equation

x*(x+7) = 638.


The rest is just arithmetic, and I sincerely hope you can complete it on your own.



Another way is to take the square root of 638: {{{sqrt(638)}}} = 25.26  and then to check numbers in vicinity of 25.


By doing in this way, I found 22 and 29 in 10 seconds  22*29 = 638.
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