(6 / 13 + 6 / 11) * 13 / 6 + 9 / 11

(6 / 13 + 6 / 11) * 13 / 6 + 9 / 11

=6/13*13/6+6/11*13/6+9/11
=1+13/11+9/11
=1+2
=3

9 * (- 110 and 11 / 13)

Original formula = 9 * (- 110-11 / 13)
=-9*110-9*11/13
=-990-99/13
=-997-8/13
=-997 8 / 13

Calculation: | 1 / 3-1 / 2 | + | 1 / 4-1 / 3 | + | 1 / 5-1 / 4 | + ·· + | 1 / 10-1 / 9 |
It's urgent! Please be more detailed!

Let's look at each item: for example, in | 1 / 3-1 / 2 | 1 / 3-1 / 2, 1 / 3-1 / 2 is less than 0, remove the absolute value sign, should become: - (1 / 3-1 / 2); including the following items are also: | 1 / 4-1 / 3 | 1 / 4-1 / 3 is also less than 0, remove the absolute value sign

10.1+10.2+10.3…… +11.9 how to calculate

10.1+10.2+10.3…… +11.9
=(10.1+10.9)*4+10.5+11+(11.1+11.9)*4+11.5
=21*4+33+23*4
=84+33+92
=209
It should be like this, for reference only, I haven't done mathematics for a long time