Question

45. Найдите значение выражения 9b+a,если 0,b(a)=4/9

Answer 1

0.b(a) = x

10x = b.(a)

100x = ba.(a)

100x - 10x = ba.(b) - b.(a)

90x = ba - b = 10b + a - b = 9b + a

0.b(a) = 4/9   (= x)

9b + a = 90x = 90*4/9 = 40