= 12* 1/8+ 12*3/4- 12* 1/6

=3/2+9-2

= 17/2

2,45 (two fifths ÷ one fifteenth)

=45÷(2/5* 15)

=45÷6

= 15/2

3, 6* 7/ 12- 1/2

=7/2- 1/2

=3

If it helps you, please adopt it. Thank you.

This is the first answer. Wish progress! ! !