2/7 + 4/7 + 3/5 =
5/9 + (2/5 + 3/5) =
Mik cần gấp
Tính bằng cách thuận tiện :
a) 3 và 2/7 - 2/5 + 5/7 - 3/5
b) 5 và 4/7 - 4/9 + 1 và 3/7 - 5/9
mik dg cần gấp ạaa
a) 3 2/7 - 2/5 + 5/7 - 3/5
= 3 + 2/7 - (2/5 + 3/5) + 5/7
= 3 + (2/7 + 5/7) - 1
= 3 + 1 - 1
= 3
b) 5 4/7 - 4/9 + 1 3/7 - 5/9
= 5 + 4/7 - 4/9 + 1 + 3/7 - 5/9
= (5 + 1) + (4/7 + 3/7) - (4/9 + 5/9)
= 6 + 1 - 1
= 6
a) \(3\dfrac{2}{7}-\dfrac{2}{5}+\dfrac{5}{7}-\dfrac{3}{5}\)
\(=\left(\dfrac{23}{7}+\dfrac{5}{7}\right)-\left(\dfrac{2}{5}+\dfrac{3}{5}\right)\)
\(=4-1\)
\(=3\)
b) \(5\dfrac{4}{7}-\dfrac{4}{9}+1\dfrac{3}{7}-\dfrac{5}{9}\)
\(=\left(\dfrac{32}{7}+\dfrac{10}{7}\right)-\left(\dfrac{4}{9}+\dfrac{5}{9}\right)\)
\(=6-1\)
\(=5\)
a) \(3\dfrac{2}{7}-\dfrac{2}{5}+\dfrac{5}{7}-\dfrac{3}{5}\)
\(=\left(\dfrac{23}{7}+\dfrac{5}{7}\right)-\left(\dfrac{2}{5}+\dfrac{3}{5}\right)\)
\(=4-1\)
\(=3\)
b) \(5\dfrac{4}{7}-\dfrac{4}{9}+1\dfrac{3}{7}-\dfrac{5}{9}\)
\(=\left(\dfrac{39}{7}+\dfrac{10}{7}\right)-\left(\dfrac{4}{9}+\dfrac{5}{9}\right)\)
\(=7-1\)
\(=6\)
tính thuận tiện : a,23/4 : 3+9/4 * 1/3 - 3/8 = b 3/5 :5/6 : 6/7 :7/8 + 2/5 +23/35 giúp mik với , mik cần gấp ^-^
a, 23/4 : 3 + 9/4 x 1/3 - 3/8
= 7,8 + 12,22 - 3,8
= 20,02 - 3,8
=16,22
b, 3/5 : 5/6 : 6/7 : 7/8 + 2/5 +23/35
=3/5 x 6/5 x 7/6 x 8/7 + 2/5 + 23/35
=24/25 + 2/5 + 23/35
=1/5 x(24/5 + 2 +23/7)
=1/5 x 353/35
=353/175
a, 23/4 : 3 + 9/4 x 1/3 - 3/8= 7,8 + 12,22 - 3,8= 20,02 - 3,8 =16,22b, 3/5 : 5/6 : 6/7 : 7/8 + 2/5 +23/35 =3/5 x 6/5 x 7/6 x 8/7 + 2/5 + 23/35=24/25 + 2/5 + 23/35=1/5 x(24/5 + 2 +23/7)=1/5 x 353/35=353/175
Giúp mik câu này mik đag cần gấp
Tính :
1)3/5 x1/7 +3/5 x6/7 -3/5
2)6/7 x4/9 + 6/7 x5/9 + 6/7
3) 9/13 x 7/12 + 9/13 x 5/12 - 9/13
4) 4/13 x5/12 +4/13 x 7/12 - 4/13
1) = \(\frac{3}{5}\)
2) =\(\frac{6}{7}\)
3)\(\frac{9}{13}\)
4)\(\frac{4}{13}\)
a, 6/7 + 3/10
b, 5/9 + 1/3
c, 5/8 - 2/5
d, 1/4 - 1/7
Giúp mik với, mik cần gấp
\(a,\dfrac{6}{7}+\dfrac{3}{10}=\dfrac{60}{70}+\dfrac{21}{70}=\dfrac{81}{70}\\ b,\dfrac{5}{9}+\dfrac{1}{3}=\dfrac{5}{9}+\dfrac{3}{9}=\dfrac{8}{9}\\ c,\dfrac{5}{8}-\dfrac{2}{5}=\dfrac{25}{40}-\dfrac{16}{40}=\dfrac{9}{40}\\ d,\dfrac{1}{4}-\dfrac{1}{7}=\dfrac{7}{28}-\dfrac{4}{28}=\dfrac{3}{28}\)
Bài 4: Tính nhanh
A) 7/8 + 7/12 + 9/8 + 5/12 =
B) 2/5 x 4/7 - 3/7 x 2/5 =
các bn giúp mik bài 4 nha mik đang cần gấp
A\(\frac{7}{8}+\frac{7}{12}+\frac{9}{8}+\frac{5}{12}\)
\(=\left(\frac{7}{12}+\frac{5}{12}\right)+\left(\frac{7}{8}+\frac{9}{8}\right)\)
\(=1+2\)
\(=3\)
1.thực hiện phép tính:
a,5/13 + -5/7 + -20/41 + 8/13 + -21/41
b,-5/7 . 2/11 + -5/7 . 9/11 +1
c, (4/5 + 1/2) . (3/13 - 8/13)
2. a, x + 4/7=7/11
b, -5/6 - x = 7/12 + -1/3
c,x - 1/4 = 5/8 . 2/3
d,x/126 = -5/9 . 4/7
giúp mik vs mn ơi, mik đnag cần rất gấp
a)16/9+3/5
b)4/13--12/7
c)-3/2+4/5
d)3/-4-1/4
e)-1/5.5/7
f)7/8.64/49
g)3/4:15/24
h)5/6:(4/3+3/4)
i)1/2-(1/3+2/3)
k)4/9+1/2.2/3
l)1/2+3/4-(3/4-4/5)
giải nhanh giúp mik vs nha do mình đang cần gấp
a\()\) 16/9 +3/5
=107/45
b\()\) 4/13--2/17
=51/221--26/221
=77/221
c\()\) -3/2+4/5
=-15/10+8/10
=-7/10
d\()\) 3/-4-1/4
=-1
e\()\) -1/5.5/7
=-1/7
f\()\) 7/8.64/49
=8/7
g\()\) 3/4.15/24
=15/32
Quy đồng mẫu số các phân số:
a, 5/7 và 12/5
b, 2/3; 4/5; 8/9.
giúp mik mik cần gấp nhé
a: 5/7=25/35
12/5=84/60
b: 2/3=30/45
4/5=36/45
8/9=40/45
a: 5/7=25/35
12/5=84/60
b: 2/3=30/45
4/5=36/45
8/9=40/45
-3/4 + -1/4 + 2/7 + 5/7 + 3/5
SOS mik đn cần gấp ạ
`(-3/4)+(-1/4)+2/7+5/7+3/5`
`=[(-3/4)+(-1/4)]+(2/7+5/7)+3/5`
`=-4/4+7/7+3/5`
`=-1+1+3/5`
`=0+3/5`
`=3/5`
-3/4 + -1/4 + 2/7 + 5/7 + 3/5
= (-3/4 + -1/4) + (2/7 + 5/7) + 3/5
= (-1 + 1) + 3/5
= 0 + 3/5
= 0
(−34)+(−14)+27+57+35(-34)+(-14)+27+57+35
=[(−34)+(−14)]+(27+57)+35=[(-34)+(-14)]+(27+57)+35
=−44+77+35=-44+77+35
=−1+1+35=-1+1+35
=0+35=0+35
=35