1.Tính
a) 1/2+1/2.-3/5
b)1/3-(1/3.2/3-3/9)
C) (-2và 1/3+1/(5/4-7/3)
d)2015/2017.3/4+3/4.2/2017+1/4
giúp mình vs
a,2/5+3/7+-3/5
b,1-5/7:x=-1/3
c,4/5*(x-1/3)=15/8
d,2/3:(2x+1/8)=7/3
e,2x+3/4=10/3-5/4
giúp mình với
a: =2/5-3/5+3/7=3/7-1/5
=15/35-7/35
=8/35
b: =>5/7:x=4/3
=>x=5/7:4/3=5/7*3/4=15/28
c: =>x-1/3=15/8:4/5=15/8*5/4=75/32
=>x=75/32+1/3=257/96
d: =>2x+1/8=2/7
=>2x=9/56
=>x=9/112
e: =>2x=10/3-5/4-3/4=10/3-2=4/3
=>x=2/3
\(a,\dfrac{2}{5}+\dfrac{3}{7}+\left(-\dfrac{3}{5}\right)\\ =\dfrac{2}{5}+\dfrac{3}{7}-\dfrac{3}{5}\\=\left(\dfrac{2}{5}-\dfrac{3}{5}\right)+\dfrac{3}{7}\\ =-\dfrac{1}{5}+\dfrac{3}{7}\\ =-\dfrac{7}{35}+\dfrac{15}{35}\\ =\dfrac{8}{35}\\ b,1-\dfrac{5}{7}:x=-\dfrac{1}{3}\\ =>\dfrac{5}{7}:x=1-\left(-\dfrac{1}{3}\right)\\ =>\dfrac{5}{7}:x=1+\dfrac{1}{3}\\ =>\dfrac{5}{7}:x=\dfrac{3}{3}+\dfrac{1}{3}\\ =>\dfrac{5}{7}:x=\dfrac{4}{3}\\ =>x=\dfrac{5}{7}:\dfrac{4}{3}\\ =>x=\dfrac{5}{7}.\dfrac{3}{4}\\ =>x=\dfrac{15}{28}\\ c,\dfrac{4}{5}\left(x-\dfrac{1}{3}\right)=\dfrac{15}{8}\\ =>x-\dfrac{1}{3}=\dfrac{15}{8}:\dfrac{4}{5}\\ =>x-\dfrac{1}{3}=\dfrac{15}{8}.\dfrac{5}{4}\\ =>x-\dfrac{1}{3}=\dfrac{75}{32}\\ =>x=\dfrac{75}{32}+\dfrac{1}{3}\\ =>x=\dfrac{257}{96}\)
\(d,\dfrac{2}{3}:\left(2x+\dfrac{1}{8}\right)=\dfrac{7}{3}\\ =>2x+\dfrac{1}{8}=\dfrac{2}{3}:\dfrac{7}{3}\\ =>2x+\dfrac{1}{8}=\dfrac{2}{3}.\dfrac{3}{7}\\ =>2x+\dfrac{1}{8}=\dfrac{2}{7}\\ =>2x=\dfrac{2}{7}-\dfrac{1}{8}\\ =>2x=\dfrac{16}{56}-\dfrac{7}{56}\\ =>2x=\dfrac{9}{56}\\ =>x=\dfrac{9}{56}:2\\ =>x=\dfrac{9}{112}\\ e,2x+\dfrac{3}{4}=\dfrac{10}{3}-\dfrac{5}{4}\\ =>e,2x+\dfrac{3}{4}=\dfrac{40}{12}-\dfrac{15}{12}\\ =>2x+\dfrac{3}{4}=\dfrac{25}{12}\\ =>2x=\dfrac{25}{12}-\dfrac{3}{4}\\ =>2x=\dfrac{25}{12}-\dfrac{9}{12}\\ =>2x=\dfrac{16}{12}\\ =>2x=\dfrac{4}{3}\\ =>x=\dfrac{4}{3}:2\\ =>x=\dfrac{4}{6}\\ =>x=\dfrac{2}{3}\)
Bài 1: Tính
a, 5/6 + 3/5
b, 11/16 - 5/8
c, 5/9 x 6/7
d, 5/4 : 3/4
giúp me
Bài 1: Tính
a, 5/6 + 3/5=40/30
b, 11/16 - 5/8=1/16
c, 5/9 x 6/7=30/63
d, 5/4 : 3/4=5/3
giúp me
a.3/4-[1/2+4/7]×1/4
b.8/9-[1/2+1/2:1/4]×1/3
c.4/5×1/3+4/5×2/9
d.6 1/3:1 6/11-1 2/17 ×1 1/3
e.2và 1/7 +3và1/5×2 và 1/2
giúp mk vs mk đang cần gấp ai đúng mk tick nha
1/ tìm x:
a) -2và 1/9 (x-7 và 1/3)=1,5
b)75/ trăm x - 3 và 1/2 = 2/5
c)( 4 và 2/3 - 2x) 2 và 1/4=11/2
d) 3/5 + 4/9 : x = 2/3
e) ( 3 và 1/2 - 2x) . 752 = 7 và 1/3
f) 0,75x + 4/9= -2 và 1/3
g) ( 3 và 1/2 -2x) . 1 và 1/3 = 7 và 1/3
h) (4,5 - 2x) . 1 và 4/7 = 11/4
giúp mình nha mn >3
tính nhanh
A=1+3-5+7-..........-2013+2015
B=1-2+3-4+...................2015-2016
C=1-2-3+4+5-6-6+8+...........+2013-2014-2015+2016
D=1-4+7-10+.....-2014+2017
E=1+2-3-3+5+6 -.......+2013+2014-2015-2016
F=1-2+3-4+..........+2015+2016
G=1+3-5-7+9+11.............-2013-2015
H=1-2-34+5-6-7+8+.................+1013-1014-1015+1016
chị kết bạn với em nha gửi lời kết bn với em nhé
Tính
a 2/8 + 1/5
b 13 / 7 - 3/5
c 5/9 x 31
d 2/7 + 4/5 : 2/3
nhanh nhanh giúp mình đi mà mình đang cần gấp
a,\(=\dfrac{9}{20}\)
b,\(=\dfrac{44}{35}\)
c,\(=\dfrac{155}{9}\)
d,\(=\dfrac{52}{35}\)
a) 3và 4/5 + 2và 1/5 b) 7 và 2/9 − 2 và 1 /9 c) 5 − 2 và 4/11 d) 5 và 1/2 − 2 và 1/3 + 2 và 1/6 e) 3và 4/5 × 2 và 1/5 f) 7và 2/9 : 2 và 1/9 g) 5 × 2và 4/11 h) 5 : 2 và 4/1
\(a,3\dfrac{4}{5}+2\dfrac{1}{5}=\dfrac{19}{5}+\dfrac{11}{5}=\dfrac{30}{5}=6\\ b,7\dfrac{2}{9}-2\dfrac{1}{9}=\dfrac{65}{9}-\dfrac{19}{9}=\dfrac{46}{9}\\ c,5-2\dfrac{4}{11}=5-\dfrac{26}{11}=\dfrac{29}{11}\\ d,5\dfrac{1}{2}-2\dfrac{1}{3}+2\dfrac{1}{6}=\dfrac{11}{2}-\dfrac{7}{3}+\dfrac{13}{6}=\dfrac{32}{6}=\dfrac{16}{3}\\ e,3\dfrac{4}{5}\times2\dfrac{1}{5}=\dfrac{19}{5}\times\dfrac{11}{5}=\dfrac{209}{25}\\ f,7\dfrac{2}{9}:2\dfrac{1}{9}=\dfrac{65}{9}:\dfrac{19}{9}=\dfrac{65}{9}\times\dfrac{9}{19}=\dfrac{65}{19}\\ g,5\times2\dfrac{4}{11}=5\times\dfrac{26}{11}=\dfrac{130}{11}\\ h,5:2\dfrac{4}{1}=5:8=\dfrac{5}{8}\)
Bài 1: Thực hiện phép tính
a) \(1-\dfrac{1}{2}+\dfrac{1}{3}\)
b) \(\dfrac{2}{5}+\dfrac{3}{5}:\dfrac{9}{10}\)
c) \(\dfrac{7}{11}.\dfrac{3}{4}+\dfrac{7}{11}.\dfrac{1}{4}+\dfrac{4}{11}\)
d) \(\left(\dfrac{3}{4}+0,5+25\%\right).2\dfrac{2}{3}\)
\(Bài 2:\text{Tìm x}\)
a) \(x+\dfrac{1}{2}=2\)
b) \(75\%x-\dfrac{1}{2}=-1\dfrac{1}{4}\)
c) \(\left|x-\dfrac{2}{5}\right|+\dfrac{7}{10}=3\)
a) \(1-\dfrac{1}{2}+\dfrac{1}{3}=\dfrac{6}{6}-\dfrac{3}{6}+\dfrac{2}{6}=\dfrac{6-3+2}{6}=\dfrac{1}{6}\)
\(b.\) \(\dfrac{2}{5}+\dfrac{3}{5}:\dfrac{9}{10}=\dfrac{2}{5}+\dfrac{3}{5}.\dfrac{10}{9}=\dfrac{2}{5}+\dfrac{2}{3}=\dfrac{6}{15}+\dfrac{10}{15}=\dfrac{6+10}{15}=\dfrac{16}{15}\)
\(c.\) \(\dfrac{7}{11}.\dfrac{3}{4}+\dfrac{7}{11}.\dfrac{1}{4}+\dfrac{4}{11}=\dfrac{21}{44}+\dfrac{7}{44}+\dfrac{4}{11}=\dfrac{21}{44}+\dfrac{7}{44}+\dfrac{16}{44}=\dfrac{21+7+16}{44}=\dfrac{44}{44}=1\)
a/\(1-\dfrac{1}{2}+\dfrac{1}{3}=\dfrac{6}{6}-\dfrac{3}{6}+\dfrac{2}{6}=\dfrac{5}{6}\)
b/\(\dfrac{2}{5}+\dfrac{3}{5}:\dfrac{9}{10}=\dfrac{2}{5}+\dfrac{3}{5}.\dfrac{10}{9}=\dfrac{2}{5}+\dfrac{2}{3}=\dfrac{6}{15}+\dfrac{10}{15}=\dfrac{16}{15}\)
d) \(\left(\dfrac{3}{4}+0,5+25\%\right).2\dfrac{2}{3}=\left(\dfrac{3}{4}+\dfrac{1}{2}+\dfrac{1}{4}\right).\dfrac{8}{3}=\left(\dfrac{3}{4}+\dfrac{2}{4}+\dfrac{1}{4}\right).\dfrac{8}{3}=\dfrac{3}{2}.\dfrac{8}{3}=4\)
Bài 1: tính
a. 1/3-(-1và2/5)+(-3và1/4)
b.5/4-(-3và1/2)-7/10
c.3/2-[(-4/7)-(1/2+5/8)]
Bài 2: thực hiện phép tính bằng cách hợp lý
a. A=(1/2-7/13-1/3)+(-6/13+1/2+1và1/3)
b.B=0,75+2/5+(1/9-1và1/2+5/4)
c.(-5/9).3/11+(-13/18).3/11
d.(-2/3).3/11+(-16/9).3/11
e.(-1/4).(-2/13)-7/24.(-2/13)
f.(-1/27).3/7+(5/9).(-3/7)
g.(-1/5+3/7):2/11+(-4/5+4/7):2/11
bài 3: thực hiện phép tính
a.0,3-4/9:4/3.6/5+1
b.1+2:(2/3-1/6).(-2,25)
c.[(1/4-0,5).2+8/3]:2
d.[(3/8-5/12).6+1/3].4
e.(4/5-1):3/5-2/3.0,5
f.0,8:{0,2-7.[1/6+(5/21-5/14)]}
Bài 4: tính theo cách hợp lý
a.4/15-(2,9-11/15)
b.(-36,75)+(37/10-63,25)-(-6,3)
c. 6,5+(-10/17)-(-7/2)-7/17
d.(-39,1).13/25-60,9.13/25
e. -5/12-3,7-7/12-6,3
f.2,8.-6/13-7,2-2,8.7/13
4:
a: =4/15-2,9+11/15=1-2,9=-1,9
b: \(=-36,75+3,7-63,25+6,3=10-100=-90\)
c: \(=6,5+3,5-\dfrac{10}{17}-\dfrac{7}{17}=10-1=9\)
d: \(=\dfrac{13}{25}\left(-39,1-60,9\right)=\dfrac{13}{25}\left(-100\right)=-52\)
e: =-5/12-7/12-3,7-6,3=-1-10=-11
f: =2,8(-6/13-7/13)-7,2=-2,8-7,2=-10