1.

`a)$1\frac{1}{4}$ +50%-11/12`

`=5/4 + 1/2 - 11/12`

`=15/12 + 6/12 - 11/12`

`=10/12`

`=5/6`

`b)$1\frac{1}{2}$+5/6 .(1-2/5)`

=3/2 + 5/6 . 3/5`

`=3/2+ 1/2 `

`=4/2`

`=2`

`c) 1/4 + 5/11 + 31/47 +18/33 + 75/100 +16/47`

`=( 1/4 + 75/100) + ( 5/11 + 18/33) + (31/47 +16/47)`

`=(25/100 +75/100) + (15/33 +18/33) + 47/47`

`= 100/100 + 33/33 +47/47`

`=1 + 1 +1`

`=3`

`d)24,37 . 53,41 -120 + 46,59 x 24,37`

`=24,37.(53,41 + 46,59) -120`

`=24,37 .100 -120`

`= 2437 -120`

`=2317`

`e) 67+31×67+41×67-57×43`

`=67×(1+31+41)-57×43`

`=67×73-57×43`

`=4891-2451`

`=2440`

Bài 2:

a)5/16-11/8 :11+0,375

=5/16-1/8+3/8

=5/16-2/16+6/16

=9/16

b)53.17+25.53+53.47-39.43

=53.(17+25+47)-39.43

=53.89-39.43

=4717 -1677

=3040

c) mờ

d)(1.3+5.7+...+3019+2021).(121212.23-232323.12)

=(1.3+5.7+...+3019+2021).0

=0