Tính
a , 4 7 × 5 2 : 5 14 = b , 3 7 × 5 2 - 5 14 =
Bài 1 : Tính
a, 7/2 - 14/3 + [ 3/4 - 7/3 ] - ( 5/6 - 7/4 )+11/2 -3
b, 7/3 - 7/5 + 11/10 - ( 2/5 - 5/6 ) + 4/15 - 4/3
a) \(\frac{7}{2}-\frac{14}{3}+\left(\frac{3}{4}-\frac{7}{3}\right)-\left(\frac{5}{6}-\frac{7}{4}\right)+\frac{11}{2}-3\)
\(=\frac{7}{2}-\frac{14}{3}+\frac{3}{4}-\frac{7}{3}-\frac{5}{6}+\frac{7}{4}+\frac{11}{2}-3\)
\(=\left(\frac{7}{2}+\frac{11}{2}\right)-\left(\frac{14}{3}+\frac{7}{3}\right)-3+\left(\frac{3}{4}+\frac{7}{4}\right)-\frac{5}{6}\)
\(=9-7-3+(\frac{5}{2}-\frac{5}{6})\)
\(=-1+\frac{5}{3}\)
\(=\frac{2}{3}\)
b) \(\frac{7}{3}-\frac{7}{5}+\frac{11}{10}-\left(\frac{2}{5}-\frac{5}{6}\right)+\frac{4}{15}-\frac{4}{3}\)
\(=\left(\frac{7}{3}-\frac{4}{3}\right)-\left(\frac{7}{5}+\frac{2}{5}\right)+(\frac{11}{10}+\frac{5}{6}+\frac{4}{15})\)
\(=1-\frac{9}{5}+\frac{11}{5}\)
\(=1-\left(\frac{9}{5}-\frac{11}{5}\right)\)
\(=1-\left(\frac{-2}{5}\right)\)
\(=1\frac{2}{5}\)
......................?
mik ko biết
mong bn thông cảm
nha ................
Tính bằng cách thuận tiện nhất
A. 3/5 * 6/7 + 3/5 : 7 + 6/5
B. 29/12 : 1/2 - 5/12 : 1/2 - 1/2
C. 2/15 * 4/7 + 4/7 * 2/3 + 4/7 : 5
D. 14/15 * 15/16 * 16/17 : 14/51
\(\frac{3}{5}\times\frac{6}{7}+\frac{3}{5}:7+\frac{6}{5}\)
\(=\frac{3}{5}\times\frac{6}{7}+\frac{3}{5}\times\frac{1}{7}+\frac{6}{5}\)
\(=\frac{3}{5}\times\left(\frac{6}{7}+\frac{1}{7}\right)+\frac{6}{5}\)
\(=\frac{3}{5}\times1+\frac{6}{5}\)
\(=\frac{3}{5}+\frac{6}{5}=\frac{9}{5}\)
~ Hok tốt ~
\(\frac{29}{12}:\frac{1}{2}-\frac{5}{12}:\frac{1}{2}-\frac{1}{2}\)
\(=\left(\frac{29}{12}-\frac{5}{12}\right):\frac{1}{2}-\frac{1}{2}\)
\(=2:\frac{1}{2}-\frac{1}{2}\)
\(=4-\frac{1}{2}=\frac{7}{2}\)
~ Hok tốt ~
\(\frac{2}{15}\times\frac{4}{7}+\frac{4}{7}\times\frac{2}{3}+\frac{4}{7}:5\)
\(=\frac{2}{15}\times\frac{4}{7}+\frac{4}{7}\times\frac{2}{3}+\frac{4}{7}\times\frac{1}{5}\)
\(=\left(\frac{2}{15}+\frac{2}{3}+\frac{1}{5}\right)\times\frac{4}{7}\)
\(=1\times\frac{4}{7}=\frac{4}{7}\)
~ Hok tốt ~
tính: a) 3/5 + 7/2 b) 14 - 1/9 c) 3/2 x 4 d) 7/8 : 5
a: =6/10+35/10=41/10
b: =126/9-1/9=125/9
c: =12/2=6
d: =7/8*1/5=7/40
Tính A) 2/3 + 5/12 - 3/5 B) 3/4 x 4/7 - 5/14
a: =40/60+25/60-36/60=29/60
b: =3/7-5/14=1/14
a) 2/3 + 5/12 - 3/5 = 40/60 + 25/60 - 36/60 = 29/60
b) 3/4 x 4/7 - 5/14 = 3/7 - 5/14 = 6/14 - 5/14 = 1/14
bài 1 tính
a) (3/7+-9/8)+(5/8+-6/14)
b) (-5/7+3/11)+(-11/14+14/-11)
c)(-4/5+2/3)+(-5/4+19/5)+(7/3.2)
d)9/16.13/4-9/4.5/16+9/16.17/4
Giải giúp mình nha . Ai nhanh mà đúng thì mình tick.
Tính nhanh
a,3/4 : ( 1/7_ 5/14) + 3/4: ( 1/2 _ 1/-3)
b,5/7 . 5/11 + 5/7 . 2/11 _ 5/7 . 14/11
Mn ơi cho mình hỏi tick kiểu gì ạ mình mới dùng web này nên ko biết
Giải giúp mình ha. Ai nhanh mà đubgs mình tick 5 cái luôn
Tính nhanh
a,3/4 : ( 1/7_ 5/14) + 3/4: ( 1/2 _ 1/-3)
b,5/7 . 5/11 + 5/7 . 2/11 _ 5/7 . 14/11
GẤP!
Tính nhanh
A)-3/7+5/13-4/7+8/13
B)-5/14-2/-14+1/8+1/8
C)-5/13-(3/5+3/13-4/10)
D)[1/8-9/7+4/6-12/7-1/2)+5/9]
a, \(\frac{-3}{7}+\frac{5}{13}-\frac{4}{7}+\frac{8}{13}\)
\(=\frac{-3}{7}-\frac{4}{7}+\frac{5}{13}+\frac{8}{13}\)
\(=-\frac{7}{7}+\frac{13}{13}=-1+1=0\)
b, \(\frac{-5}{14}-\frac{2}{-14}+\frac{1}{8}+\frac{1}{8}\)
\(=\frac{-5}{14}+\frac{2}{14}+\frac{1}{8}+\frac{1}{8}\)
\(=-\frac{3}{14}+\frac{1}{4}=\frac{1}{28}\)
c,\(-\frac{5}{13}-\left(\frac{3}{5}+\frac{3}{13}-\frac{4}{10}\right)\)
\(=-\frac{5}{13}-\frac{3}{13}-\frac{3}{5}+\frac{4}{10}\)
\(=-\frac{8}{13}-\frac{3}{5}+\frac{4}{10}=-\frac{79}{65}+\frac{4}{10}=-\frac{53}{65}\)
d, \(\left[\left(\frac{1}{8}-\frac{9}{7}+\frac{4}{6}-\frac{12}{7}-\frac{1}{2}\right)+\frac{5}{9}\right]\)
\(=\left[\left(\frac{1}{8}-\frac{9}{7}+\frac{2}{3}-\frac{12}{7}-\frac{1}{2}\right)+\frac{5}{9}\right]\)
\(=\left[\left(\frac{1}{8}-\frac{1}{2}-\frac{9}{7}-\frac{12}{7}+\frac{2}{3}\right)+\frac{5}{9}\right]\)
\(=-\frac{65}{24}+\frac{5}{9}=-2\frac{11}{72}\)
a)-3/7+5/13-4/7+8/13
=-3/7-4/7+5/13+8/13
=-7/7+13/13
=-1+1
=0
tính :
a) 4/5 + 2/3 + 1/9
b) 3/7 + 11/14 + 19/28
c) 1/2 + 1/7 + -1/5
d) 7/8 + 5/16 + -3/4
e) 1/4 + 5/12 + -1/13
g) 2/3 + 3/8 + -5/12
\(a,\dfrac{4}{5}+\dfrac{2}{3}+\dfrac{1}{9}=\dfrac{12}{15}+\dfrac{10}{15}+\dfrac{1}{9}=\dfrac{22}{15}+\dfrac{1}{9}=\dfrac{66}{45}+\dfrac{5}{45}=\dfrac{71}{45}\)
\(b,\dfrac{3}{7}+\dfrac{11}{14}+\dfrac{19}{28}=\dfrac{12}{28}+\dfrac{22}{28}+\dfrac{19}{28}=\dfrac{53}{28}\)
\(c,\dfrac{1}{2}+\dfrac{1}{7}+\dfrac{-1}{5}=\dfrac{7}{14}+\dfrac{2}{14}+\dfrac{-1}{5}=\dfrac{9}{14}+\dfrac{-1}{5}=\dfrac{45}{70}+\dfrac{-14}{70}=\dfrac{31}{70}\)
\(d,\dfrac{7}{8}+\dfrac{5}{16}+\dfrac{-3}{4}=\dfrac{14}{16}+\dfrac{5}{16}+\dfrac{-12}{16}=\dfrac{7}{16}\)
\(e,\dfrac{1}{4}+\dfrac{5}{12}+\dfrac{-1}{13}=\dfrac{3}{12}+\dfrac{5}{12}+\dfrac{-1}{13}=\dfrac{8}{12}+\dfrac{-1}{13}=\dfrac{2}{3}+\dfrac{-1}{13}=\dfrac{26}{39}+\dfrac{-3}{39}=\dfrac{23}{39}\)
\(g,\dfrac{2}{3}+\dfrac{3}{8}+\dfrac{-5}{12}=\dfrac{16}{24}+\dfrac{9}{24}+\dfrac{-5}{12}=\dfrac{25}{24}+\dfrac{-5}{12}=\dfrac{25}{24}+\dfrac{-10}{24}=\dfrac{15}{24}\)
Bài 1 . Tính nhanh :
A = 6/7 + 1/7 . 2/7 + 1/7 . 5/7
B = 4/9 . 13/3 - 4/3 . 40/9
M = 8/3 . 2/5 . 3/8 . 10 . 19/2
N = 5/7 . 5/11 + 5/7 . 2/11 - 5/7 . 14/11
B=4*13/9*3-4/3*40/9
B=4/3*13/9-4/3*40/9
B=4/3*(13/9-40/9)
B=4/3*(-27)/9
B=4*(-3)/9
B=-4
A=6/7 + 1/7.(2/7+5/7)
A=6/7 + 1/7.7/7=6/7+1/7.1
A=6/7+1/7=7/7=1
M=8/3*2/5*3/8*10*19/2
M=(8/3*3/8)*(2/5*10)*19/2
M=1*4*19/2
M=28