Question

det valorile natural a lu lui A :

2\7mai mic A\56               2\3mai mic 54\A mai mic 9\13

3\5mai mic A\12mai mic 1

Answer 1

2/7<A/56
2x56<7A
7A>112
A>112/7
A>16

2/3<54/A<9/13
2A<54x3
A<162/2
A<81
54/A<9/13
54x13<9A
9A>702
A>702/9
A>78
⇒A∈(78,81)

3/5<A/12<1
3/5<A/12
3x12<5A
5A>36
A>36/5
A>7,2
A/12<1
A<12
⇒A∈(7,2;12)