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Using the digits 1 to 9, at most one time each, create an equation where x has the smallest possible value. (▢ is empty values)

▢/▢ (▢x+▢) +▢x=▢x+▢

User Deniesha
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1 Answer

8 votes

Answer:

1/8(7x +2) +3x = 4x +9

Explanation:

The value of x will be smallest when it is most negative. Here, that will occur when the numerator of the rational solution for x is as large a positive number as possible, and the denominator is a small negative number.

If we call the spaces a, b, ..., g, then the value of x is ...

x = (bg -ad)/(ac +b(e-f))

This is smallest (most negative) when bg is as large as possible (8·9), and ad is as small as possible (1·2). Then values for c, e, f can be chosen to make the denominator -1. The solution for x looks like ...

x = (8·9 -1·2)/(1·7 +8(3 -4)) = 70/-1 = -70

The smallest possible value of x is -70. One way to obtain that value is ...

1/8(7x +2) +3x = 4x +9

_____

There are numerous ways to obtain "indeterminate" results where the equation reduces to one with no solution. And there are a number of ways to have the solution be infinity: (ac-b(e-f)) = 0.

User Ian Elliott
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