Giúp mình làm bài 1,2 nhé

#wheijx.

`1.`

`a)` `2024 xx 2025 xx 2026 xx 2027 xx 2028 xx ( 1288 - 56 xx 23 )`

`= 2024 xx 2025 xx 2026 xx 2027 xx 2028 xx ( 1288 - 1288 )`

`= 2024 xx 2025 xx 2026 xx 2027 xx 2028 xx 0`

`= 0`

`b)` `1/5 + 5/9 + 4/5 + 1/9 + 3/9`

`= ( 1/5 + 4/5 ) + ( 5/9 + 1/9 + 3/9 )`

`= 5/5 + 9/9`

`= 1 + 1`

`= 2`

`c)` `1/3 + 1/6 + 4/3 + 2/6 + 2/3 + 5/6`

`= ( 1/3 + 4/3 + 2/3 ) + ( 1/6 + 2/6 + 5/6 )`

`= 7/3 + 8/6`

`= 7/3 + 4/3`

`= 11/3`

`2.`

`( 23 xx 27 - 27 xx 20 ) + ( 20 xx 18 - 18 xx 17 )`

`= 27 xx ( 23 - 20 ) + 18 xx ( 20 - 17 )`

`= 27 xx 3 + 18 xx 3`

`= ( 27 + 18 ) xx 3`

`= 45 xx 3`

`= 135`

Bài `1:`

`A,2024xx2025xx2026xx2027xx2028xx(1288-56xx23)`

`=2024xx2025xx2026xx2027xx2028xx(1288-1288)`

`=2024xx2025xx2026xx2027xx2028xx0`

`=0`

`a,1/5+5/9+4/5+1/9+3/9`

`=(1/5+4/5)+(5/9+1/9+3/9)`

`=5/5+(6/9+3/9)`

`=5/5+9/9`

`=1+1`

`=2`

`b,1/3+1/6+4/3+2/6+2/3+5/6`

`=(1/3+4/3+2/3)+(1/6+2/6+5/6)`

`=(5/3+2/3)+(3/6+5/6)`

`=7/3+8/6`

`=7/3+4/3`

`=11/3`

Bài `2:`

`(23xx27-27xx20)+(20xx18-18xx17)`

`=(23-20)xx27+(20-17)xx18`

`=3xx27+3xx18`

`=3xx(27+18)`

`=3xx45`

`=135`