Đáp án:
Không viết lại đề
Giải thích các bước giải:
Bài 2:
`a)`
`→A=2/3+(-1/3)`
`→A=1/3`
`b)`
`→B=(-3)/4 . 68/13 + (-3)/4 . 36/13`
`→B=(-3)/4 . (68/13+36/13)`
`→B=(-3)/4 . 8`
`→B=-6`
`c)`
`→C=11/20 . (-2/5)`
`→C=-11/50`
`d)`
`→D=(-5/21). 5/4+5/21 . 5/4`
`→D=5/4(-5/21+5/21)`
`→D=5/4 . 0=0`
`e)`
`→E=5/9 .(-3/22) +5/9 . (-3/5)`
`→E=5/9(-3/22-3/5)`
`→E=5/9 . (-81/110)`
`→E=-9/22`
`f)`
`→P=(0,75-0,6+3/17+3/13):(2,75-2,2+11/7+11/13)`
`→P=(3/4-3/5+3/17+3/13):(11/4-11/5+11/7+11/3)`
`→P=[3.(1/4-1/5+1/17+1/13)]:[11.(1/4-1/5+1/7+1/13)]`
`→P=3/11`
