How to calculate 9.6 minus (7.6 times 1.2)

How to calculate 9.6 minus (7.6 times 1.2)

9.6-7.6×1.2=8×1.2-7.6×1.2=（8-7.6）×1.2=0.4×1.2=0.48

How to solve 18 / 19 of 24 × 24 × 19

24*24*19/18=3*8*3*8*19/(2*3*3)=4*8*19=608

How to calculate 18 / 19 of 24-24x19

24-24x118 / 9
=24x (18 / 1-19)
=24x19 / 1
=24 out of 19

1 / 6 × 9 + 1 / 9 × 12 + 1 / 12 × 15 + 1 / 15 × 18 + 1 / 18 × 21 + 1 / 21 × 24
/It means fractional line. It's also a simple algorithm. When answering questions, you can use shift plus

1/6×9＋1/9×12＋1/12×15＋1/15×18＋1/18×21＋1/21×24
=1/3(1/6-1/9)+1/3(1/9-1/12)+1/3(1/12-1/15)+1/3(1/15-1/18)
+1/3(1/18-1/21)+1/3(1/21-1/24)
=1/3(1/6-1/9+1/9-…… +1/21-1/24)
=1/3(1/6-1/24)
=1/24