a) 9/8 + 7/8 - (17/7 - 3/7) = 16/8 - 14/7 = 2 - 2 = 0

b) (15,27 - 1,14) - 4,13 = 14,13 - 4,13 = 10

c) (60 - 13,75) - 26,25 = 46,25 - 26,25= 20

ai mk mk lại

15,27 - (4,13+1,14)

=15,27 - 5,27

= 10,27

 = 19/37 - 19/37 + 1

= 0/37 + 1

= 0/37 + 37/37

=1

1 + 19/37 - 19/37

1 + 0 = 1

kết quả là: 249/629

\(\frac{19}{37}+\left(1-\frac{19}{17}\right)\)

= \(\frac{19}{37}+\left(\frac{-2}{17}\right)\)

= \(\frac{249}{629}\)

`a,`

`34,67+5,42+4,58`

`= 34,67+(5,42+4,58)=34,67+10=44,67`

`b,`

`15,27 \times 2 \times 0,5`

`= 15,27 \times (2 \times 0,5)`

`= 15,27 \times 1=15,27`

`c,`

`45,28 \times 45 + 45,28 \times 55`

`= 45,28 \times (45+55)`

`= 45,28 \times 100=4528`

a.

34,67 + 5,42 + 4,58

= (34,67 + 5,42) + 4,58= 40,09 + 4,58 = 44,67 

b. 15,27 x 2 x 0.5

= (15,27 x 2) x 0.5 = 30,54 x 0,5 = 15,27

c. 45,28  x45 + 45,28 x 55

=  45,28 x (45 + 55)

= 45,28 x 100 = 4528

19.9+9.(37+43)+9

=19.9+9.80+9

=9.(19+80+1)

=9.100

=900

`#Ya`

`= 19 × 9 + 9 × 80 + 9 × 1`

`= 9 × ( 19 + 80 + 1 )`

`= 9 × 100= 900`

19/37+1-19/37

=(19/37-19/37)+1

=0+1

=1

9/8-(17/7-3/7)+7/8

=(9/8+7/8)-(17/7-3/7)

=2-2

=0

1/2+3/4+1/2

=(1/2+1/2)+3/4

=1+3/4

=7/4

19/37 + 1 - 19/37 = (19/37 - 19/37) + 1 = 1

9/8 - (17/7 - 3/7) + 7/8 = (9/8 + 7/8) - (17/7 - 3/7) = 16/8 - 14/7 = 2 - 2 = 0

1/2 + 3/4 + 1/2 = (1/2 + 1/2) + 3/4 = 1 + 3/4 = 7/4