x − n u mb er 31 x + 40 = 200 − x ∣ a dd x 32 x + 40 = 200 ∣ s u b t r a c t 40 32 x = 160 ∣ d i v i d e b y 32 x = 5 N u mb er i s 5.
5 ;
The unknown number is found to be 5 by setting up the equation based on the given conditions and solving for x step by step. After simplifying the equation, we arrive at the solution. Therefore, x = 5 .
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