Question

determinati num.naturale de forma.....x=2, 2y.1y9,y19.

Answer 1

y{0,1,2,3,4,5,6,7,8,9}
prima varianta:x={2,20,109,019}=>incorect=>y≠0
a-II-a varianta:x={2,21,119,119}=>corect=>y=1
a-II-a varianta:x={2,22,129,219}=>corect=>y=2
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ultima varianta:x={2,29,199,919}=>corect=>y=9
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=>y={1,2,3,4,5,6,7,8,9}=>x={2,21,119,22129,219,31,139,319,...,919}