Đáp án:
`a)` `5/9`
`b)` `2`
`c)` `5`
`d)` `1`
Giải thích các bước giải:
`a)` `15/13-(4/9+2/13) `
`=15/13-4/9-2/13`
`=(15/13-2/13)-4/9`
`=1-4/9`
`=5/9`
`b)` `(7(4)/9-4(7)/11)-(3(4)/9-2(7)/11)`
`=7(4)/9-4(7)/11-3(4)/9+2(7)/11`
`=(7(4)/9-3(4)/9)-(4/(7)/11-2(7)/11`
`=4-2`
`=2`
`c)` `(-7)/9×4/11+(-7)/9×7/11+5(7)/9`
`=(-7)/9×(4/11+7/11)+5(7)/9`
`=(-7)/9+5(7)/9`
`=5`
`d)` `18/23+5/23×1(2)/29-5/23×2/29`
`=18/23+5/23×(1(2)/29-2/29)`
`=18/23+5/23`
`=1`