`@` `\text {Ans}`
`\downarrow`
`1)`
`2/5-1/4+3/10`
`= 3/20+3/10`
`=9/20`
`2)`
`-2/5 \div (1-1/10)`
`= -2/5 \div 9/10`
`= -4/9`
`3)`
`7/8*4/9 + 1/14 \div 5/14`
`= 7/18+1/14*14/5`
`= 7/18+1/5`
`=53/90`
`4)`
`2/7*3/11 + 2/7*8/11`
`= 2/7*(3/11+8/11)`
`= 2/7*11/11`
`= 2/7*1=2/7`
`5)`
`2 3/7 + 1 4/7`
`= 17/7 + 11/7`
`= 28/7=4`
`6)`
`-2/3*4/5+1/5 \div 9/11`
`= -8/15 + 1/5 * 11/9`
`= -8/15 + 11/45`
`= -13/45`
`7)`
`(-6,2 \div 2+3,7) \div 0,2`
`= (-3,1+3,7) \div 0,2`
`= 0,6 \div 0,2`
`= 0,3`
`8)`
`2/3+1/5*10/7`
`= 2/3+2/7`
`= 20/21`
`9)`
`2/7+5/7*14/25`
`= 2/7+2/5`
`=24/35`
`10)`
`7/12-27/7*1/18`
`= 7/12 - 3/14`
`= 31/84`
`11)`
`3/10*(-5/6)-1/8`
`= -1/4-1/8`
`= -3/8`
`12)`
`(-4/9)*3/8+1/18`
`= -1/6+1/18`
`= -1/9`
`13)`
`2/7+28/27 \div (-4/9)`
`= 2/7+ (-7/3)`
`= -43/21`
`# \text {NgMH101}`
1) 2/5 - 1/4 + 3/10
= 8/20 + 6/20 - 5/20
= 9/20
2) -2/5 : (1 - 1/10)
= -2/5 : 9/10
= -4/9
3) 7/8 . 4/9 + 1/14 : 5/14
= 7/18 + 1/5
= 53/90
4) 2/7 . 3/11 + 2/7 . 8/11
= 2/7 . (3/11 + 8/11)
= 2/7 . 1
= 2/7
5) 2 3/7 + 1 4/7
= 17/7 + 11/7
= 28/7
= 4
6) -2/3 . 4/5 + 1/5 : 9/11
= -8/15 + 11/45
= -13/45
7) (-6,2 : 2 + 3,7) : 0,2
= 0,6 : 0,2
= 3
8) 2/3 + 1/5 . 10/7
= 2/3 + 2/7
= 20/21
9) 2/7 + 5/7 . 14/25
= 2/7 + 2/5
= 24/35
10) 7/12 - 27/7 . 1/18
= 7/12 - 3/14
= 31/84
11) 3/10 . (-5/6) - 1/8
= -1/4 - 1/8
= -3/8
12) (-4/9) . 3/8 + 1/18
= -1/6 + 1/18
= -1/9
13) 2/7 + 28/27 : (-4/9)
= 2/7 - 7/3
= -43/21
