a) 3/5 + ( -4/3) + ( -3/4)
b) X – 2/7=7/21
c) 11/12 – ( 2/5+ X ) = 2/3
d) 3/7 – X = 1/4 – ( – 3/5 )
e) 3/35 – ( 3/5 + X ) = 2/7
f) 2/9 – (1/3- X ) = 5/6
g) 4 1/5 : (-2 4/5)
nếu câu nào dài quá thì ghi mỗi kết quả phép tính cũng đc
a) 3/5 + ( -4/3) + ( -3/4) b) X – 2/7=7/21 c) 11/12 – ( 2/5+ X ) = 2/3 d) 3/7 – X = 1/4 – ( – 3/5 ) e) 3/35 – ( 3/5 + X ) = 2/7 f) 2/9 – (1/3- X )
By Melanie
`a) 3/5 + (-4)/3 + (-3)/4`
`= 36/60 – 80/60 – 45/60`
` = -89/60`
`b) x – 2/7 = 7/21`
`=> x – 2/7 = 1/3`
`=> x = 1/3 + 2/7`
`=> x = 13/21`
Vậy `x=13/21`
`c) 11/12 – (2/5 + x) =2/3`
`=> 2/5 + x = 11/12 – 2/3`
`=> 2/5 + x = 1/4`
`=> x = 1/4 – 2/5`
`=> x = -3/20`
Vậy `x=-3/20`
`d) 3/7 – x = 1/4 – (-3/5)`
`=> 3/7- x = 17/20`
`=> x = 3/7 – 17/20`
`=>x = -59/140`
Vậy `x = -59/140`
`e) 3/35 – (3/5 + x) = 2/7`
`=> 3/5 + x = 3/35 – 2/7`
`=> 3/5 + x = -1/5`
`=> x = -1/5 – 3/5`
`=> x = -4/5`
Vậy `x=-4/5`
`f) 2/9 – (1/3 – x) = 5/6`
`=> 1/3 – x= 2/9 – 5/6`
`=> 1/3 – x = -11/18`
`=> x = 1/3+ 11/18`
`=> x = 17/18`
Vậy `x=17/18`
`g) 4 1/5 : (-2 4/5)`
` = 21/5 : (-14)/5`
` = 21/5 . (-5)/14`
` = -3/2`
`a)3/5+(-4/3)+(-3/4)`
`=36/60+(-80/60)+(-45/60)`
`=(36-80-45)/(60)`
`=-89/60`
`b)x-2/7=7/(21)`
`x-2/7=1/3`
`x=1/3+2/7`
`x=7/(21)+6/(21)`
`x=13/21`
Vậy `x=13/21`
`c)11/12-(2/5+x)=2/3`
`2/5+x=11/12 – 2/3`
`2/5+x=11/12-8/(12)`
`2/5+x=3/(12)`
`2/5 +x=1/4`
`x=1/4 – 2/5`
`x=5/(20)-8/(20)`
`x=-3/(20)`
Vậy `x=-3/(20)`
`d)3/7-x=1/4-(-3/5)`
`3/7-x=1/4+3/5`
`3/7-x=5/(20)+12/20`
`3/7-x=17/20`
`x=3/7 – 17/20`
`x=(-59)/(140)`
Vậy `x=(-59)/(140)`
`e)3/(35)-(3/5+x)=2/7`
`3/5+x=3/(35) – 2/7`
`3/5 + x=-1/5`
`x=-1/5 – 3/5`
`x=-4/5`
Vậy `x=-4/5`
`f)2/9 – (1/3-x)=5/6`
`1/3-x=2/9-5/6`
`1/3-x=-11/18`
`x=1/3-(-11/18)`
`x=1/3+11/18`
`x=17/18`
Vậy `x=17/18`
`g) 4 1/5 : (-2 4/5)`
`=(21)/5 : (-14/5)`
`=(21)/5 . (-5/14)`
`=-3/2`