12
=
1 × 22 × 2
=
24
12
=
1 × 32 × 3
=
36
12
=
1 × 42 × 4
=
48
12
=
1 × 52 × 5
=
510
(Multiplying both the numerator and the denominator by 2)
(Multiplying both the numerator and the denominator by 3)
(Multiplying both the numerator and the denominator by 4)
(Multiplying both the numerator and the denominator by 5)