Question

Tìm số tự nhiên y biết :

a. 40 <_ y < 49

b. 189 < 9y <_ 945 

Answer 1

a,\(40\le y< 49\Rightarrow y\in\left\{40;41;42;43;44;45;46;47;48\right\}\)

b,\(189< 9y\le945\Rightarrow9y\in\left\{190;191;192;...;944;945\right\}\)

=>\(y\in\left\{22;23;24;...;105\right\}\)

Answer 2

Cảm ơn bạn nhiều. 

Answer 3

ko biết

Answer 4

a.40<41,42,43,44,45,46,47,48<49

b.189<900,901,902,903,904,.........944<945