Question

Tim so thich hop thay cho a sao cho \(\frac{a}{36}\) la phan so lon nhat thoa man dieu kien \(\frac{1}{9}\)<\(\frac{a}{36}\)<\(\frac{1}{2}\)

Answer 1

Quy đồng mẫu số :

Ta có 36 chia hết cho 9 và 2

=> MSC sẽ là 36

36 : 9 = 4 ; 36 : 2 = 18

\(\frac{1}{9}=\frac{1.4}{9.4}=\frac{4}{36}\)

\(\frac{1}{2}=\frac{1.18}{2.18}=\frac{18}{36}\)

Vậy a = { 5 ; 6 ; 7 ; 8 ; ... ; 16 ; 17 }

Answer 2

\(\frac{1}{9}< \frac{a}{36}< \frac{1}{2}\)

\(\Rightarrow\frac{1}{9}=\frac{4}{36};\frac{a}{36}=\frac{a}{36};\frac{1}{2}=\frac{18}{36}\)

\(\Rightarrow\frac{4}{36}< \frac{a}{36}< \frac{18}{36}\)

\(\Rightarrow a\in\left\{5;6;7;8;9;10;11;12;13;14;15;16;17\right\}\)

a lớn nhất: \(\Rightarrow a=17\)