Tính:
A,2/5x4/3=..........
B,5/11x2=............
C,3/7x8/5=...........
D,8/21:2/7=..........
E,9/5:3/5=..........
G,2:1/3=..........
Tính:
a) -5/7(14/5 - 7/10) : |-2/3| - 3/4(8/9 + 16/3) + 10/3(1/3 + 1/5)
b) 17/-26(1/6 - 5/3) : 17/13 - 20/3(2/5 - 1/4) + 2/3(6/5 - 9/2)
c) -8/9(9/8 - 3/2) + 5/4 : (5/2 - 15/4) - 3/4(10/9 - 8/3) : (-1/3)
d) 21/10 : (12/5 - 9/10) . (-4/7) - 3/2(1/6 - 7/12) + 1/5(3/2 - 1/4)
a) Ta có: \(\dfrac{-5}{7}\left(\dfrac{14}{5}-\dfrac{7}{10}\right):\left|-\dfrac{2}{3}\right|-\dfrac{3}{4}\left(\dfrac{8}{9}+\dfrac{16}{3}\right)+\dfrac{10}{3}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)\)
\(=\dfrac{-5}{7}\cdot\dfrac{3}{2}\cdot\dfrac{21}{10}-\dfrac{3}{4}\cdot\dfrac{56}{3}+\dfrac{10}{3}\cdot\dfrac{8}{15}\)
\(=\dfrac{-9}{4}-14+\dfrac{16}{9}\)
\(=\dfrac{-1621}{126}\)
b) Ta có: \(\dfrac{17}{-26}\cdot\left(\dfrac{1}{6}-\dfrac{5}{3}\right):\dfrac{17}{13}-\dfrac{20}{3}\left(\dfrac{2}{5}-\dfrac{1}{4}\right)+\dfrac{2}{3}\left(\dfrac{6}{5}-\dfrac{9}{2}\right)\)
\(=\dfrac{-17}{26}\cdot\dfrac{13}{17}\cdot\dfrac{-3}{2}-\dfrac{20}{3}\cdot\dfrac{3}{20}+\dfrac{2}{3}\cdot\dfrac{-33}{10}\)
\(=\dfrac{3}{4}-1-\dfrac{11}{5}\)
\(=-\dfrac{49}{20}\)
Tính:
a, 5/-14. 7/-19
b, -15/4 .( 16/-25 )
c, 3/-10 .( -15/-2 )
d, -5/7 . ( 21/-10 )
e, 10/-3. (6/-5)
f, 21/-9 . ( -6/14 )
g, -10/9 . ( 36/20 )
a, 5/-14. 7/-19=8/38
b, -15/4 .( 16/-25 )=12/5
c, 3/-10 .( -15/-2 )=
d, -5/7 . ( 21/-10 )=-9/4
e, 10/-3. (6/-5)==4
f, 21/-9 . ( -6/14 )=1
g, -10/9 . ( 36/20 )=-2
Tính:
a, 6/7 : ( -5/3 )
b, 2/5 : ( 8/-15 )
c, 2/4 : ( -3/-7 )
d, -8/3 : ( -4/16 )
e, 5/-7 : ( 9/ -3 )
a: \(=\dfrac{6}{7}\cdot\dfrac{-3}{5}=\dfrac{-18}{35}\)
b: \(=\dfrac{2}{5}\cdot\dfrac{-15}{8}=\dfrac{-30}{40}=-\dfrac{3}{4}\)
c: \(=\dfrac{2}{4}\cdot\dfrac{7}{3}=\dfrac{1}{2}\cdot\dfrac{7}{3}=\dfrac{7}{6}\)
d: \(=\dfrac{8}{3}\cdot\dfrac{16}{4}=\dfrac{128}{12}=\dfrac{32}{3}\)
a)-18/35
b)-3/4
c)7/6
d)32/3
e)5/21
sai thì xin lỗi nhé bn
Tính:
a) \(\dfrac{3}{8}+\dfrac{7}{8}\) b) \(\dfrac{7}{9}-\dfrac{4}{9}\) c) \(\dfrac{5}{6}+\dfrac{1}{8}\) d) \(\dfrac{9}{15}-\dfrac{2}{5}\)
e) \(\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}\) g) \(\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}\) h) \(\dfrac{23}{7}-\dfrac{4}{7}+\dfrac{2}{7}\)
a: \(\dfrac{3}{8}+\dfrac{7}{8}=\dfrac{3+7}{8}=\dfrac{10}{8}=\dfrac{5}{4}\)
b: \(\dfrac{7}{9}-\dfrac{4}{9}=\dfrac{7-4}{9}=\dfrac{3}{9}=\dfrac{1}{3}\)
c: \(\dfrac{5}{6}+\dfrac{1}{8}=\dfrac{20}{24}+\dfrac{3}{24}=\dfrac{20+3}{24}=\dfrac{23}{24}\)
d: \(\dfrac{9}{15}-\dfrac{2}{5}=\dfrac{3}{5}-\dfrac{2}{5}=\dfrac{3-2}{5}=\dfrac{1}{5}\)
e: \(\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}=\dfrac{2+3+9}{5}=\dfrac{14}{5}\)
g: \(\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}=\dfrac{8-1-3}{10}=\dfrac{4}{10}=\dfrac{2}{5}\)
h: \(\dfrac{23}{7}-\dfrac{4}{7}+\dfrac{2}{7}=\dfrac{23-4+2}{7}=\dfrac{21}{7}=3\)
Tính:
a) \(\dfrac{5}{9}:\dfrac{7}{3}\) b) \(\dfrac{2}{7}:\dfrac{8}{5}\) c) \(\dfrac{4}{15}:\dfrac{2}{5}\) d) \(\dfrac{7}{9}:\dfrac{21}{9}\)
a) $\frac{5}{9}:\frac{7}{3} = \frac{5}{9} \times \frac{3}{7} = \frac{{15}}{{63}} = \frac{5}{{21}}$
b) $\frac{2}{7}:\frac{8}{5} = \frac{2}{7} \times \frac{5}{8} = \frac{{10}}{{56}} = \frac{5}{{28}}$
c) $\frac{4}{{15}}:\frac{2}{5} = \frac{4}{{15}} \times \frac{5}{2} = \frac{{20}}{{30}} = \frac{2}{3}$
d) $\frac{7}{9}:\frac{{21}}{9} = \frac{7}{9} \times \frac{9}{{21}} = \frac{{63}}{{189}} = \frac{1}{3}$
Tính:
a) \(\dfrac{7}{2}+5\) b) \(9+\dfrac{12}{13}\) c) \(8-\dfrac{9}{11}\) d) \(\dfrac{21}{5}-3\)
a: \(\dfrac{7}{2}+5=\dfrac{7}{2}+\dfrac{10}{2}=\dfrac{17}{2}\)
b: \(9+\dfrac{12}{13}=\dfrac{117}{13}+\dfrac{12}{13}=\dfrac{129}{13}\)
c: \(8-\dfrac{9}{11}=\dfrac{88}{11}-\dfrac{9}{11}=\dfrac{88-9}{11}=\dfrac{79}{11}\)
d: \(\dfrac{21}{5}-3=\dfrac{21}{5}-\dfrac{15}{5}=\dfrac{6}{5}\)
Bài 1 Tính nhanh
a) -3/7 + 5/13 + 3/7
b) -5/21+-2/21+8/24
c) -5/11+(-6/11+2)
d) (-1/32+1/2)+15/32
e)5/17+ -6/13 + 3/4 + 7/-13+12/17
f) 7/23+-18/18+-4/9+16/23+-5/8
g)1/3+-3/4+3/5+-1/36+1/15+-2/9
h)-1/2+1/3+-1/4+-2/8+4/18+4/9
a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\)
=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\)
=\(0+\dfrac{5}{13}\)
=\(\dfrac{5}{13}\)
Tính:
a) 6/7 + 7/8 b) 4/5 - 2/3 c) 2/3 x 4/9 d) 1/5 : 2/7
a) \(\dfrac{6}{7}+\dfrac{7}{8}=\dfrac{48}{56}+\dfrac{49}{56}=\dfrac{97}{56}\)
b) \(\dfrac{4}{5}-\dfrac{2}{3}=\dfrac{12}{15}-\dfrac{10}{15}=\dfrac{2}{15}\)
c) \(\dfrac{2}{3}.\dfrac{4}{9}=\dfrac{8}{27}\)
d) \(\dfrac{1}{5}:\dfrac{2}{7}=\dfrac{1}{5}.\dfrac{7}{2}=\dfrac{7}{10}\)
a: =48/56+49/56
=97/56
b: =12/15-10/15
=2/15
c: =(2*4)/(3*9)=8/27
d: =1/5*7/2=7/10
` 6/7 + 7/8 = 48/56 + 49/56 = 97/56`
` 4/5 - 2/3 = 12/15 - 10/15 = 2/15`
` 2/3 xx 4/9 = 8/27`
` 1/5 : 2/7 = 1/5 . 7/2 = 7/10`
Tính:
a, 5/9 + 2/3 =
b, 7/8 x 5/7 =
c, 6/5 : 2/3 =
d, 7/2 - 29/14 =
a) 5/9+ 6/9= 11/9
b) 5/8
c) 6/5 x 3/2 = 9/5
d) 49/14- 29/14= 20/14 = 10/7
a, 5/9 + 2/3 = 11/9
b, 7/8 x 5/7 = 5/8
c, 6/5 : 2/3 = 9/5
d, 7/2 - 29/14 =10/7