Tính a) 7 12 + 1 4
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Khách
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CM
Cao Minh Tâm
22 tháng 2 2018
Đúng(0)
Những câu hỏi liên quan
2 tháng 4 2021
c) Ta có: \(\dfrac{3}{5}+\dfrac{-5}{20}+\dfrac{30}{75}+\dfrac{-7}{4}\)
\(=\dfrac{3}{5}+\dfrac{2}{5}+\dfrac{-1}{4}+\dfrac{-7}{4}\)
\(=1-2=-1\)
2 tháng 4 2021
Giải:
a)-1/12+4/3=-1/12+16/12=15/12=5/4
b)(-4/14-3/15)-(1/5-20/35-(-1)).7
=-17/35-22/35.7
=-17/35-22/5
=-171/35
c)3/5+-5/20+30/75+-7/4
=3/5+-1/4+2/5+-7/4
=(3/5+2/5)+(-1/4+-7/4)
=1+-2
=-1
d)5/6.-12/14+7/13
=-5/7+7/13
=-16/91
e)2/-9-5/-36-1/4
=-1/12-1/4
=-1/3
f)2/23+-5/12+7/18+21/23+-7/12
=(2/23+21/23)+(-5/12+-7/12)+7/18
=1+-1+7/18
=7/18
OT
2
21 tháng 2 2022
a: \(=\left(\dfrac{4}{9}+\dfrac{5}{9}\right)+\left(\dfrac{1}{8}+\dfrac{7}{8}\right)=1+1=2\)
b: \(=\left(\dfrac{1}{6}+\dfrac{4}{6}+\dfrac{7}{6}\right)+\left(\dfrac{5}{12}+\dfrac{7}{12}\right)=2+1=3\)
LN
25 tháng 2 2019
\(A=\frac{3}{7}+\frac{4}{9}+\frac{4}{7}+\frac{7}{11}\)
\(A=1+\frac{4}{9}+\frac{7}{11}\)
\(A==\frac{76}{33}\)
\(B=\frac{1}{8}+\frac{1}{12}+\frac{3}{8}+\frac{5}{12}\)
\(B=\frac{1}{2}+\frac{1}{2}\)
\(B=\frac{1}{4}\)
14 tháng 2 2022
a: \(=\dfrac{-5}{8}+\dfrac{7}{12}=\dfrac{-15}{24}+\dfrac{14}{24}=\dfrac{-1}{24}\)
b: \(=\dfrac{3}{4}-\dfrac{5}{6}+\dfrac{11}{12}=\dfrac{9}{12}-\dfrac{10}{12}+\dfrac{11}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)
c: \(=\dfrac{6}{36}-\dfrac{1}{36}=\dfrac{5}{36}\)
d: \(=\dfrac{5}{12}+\dfrac{5}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)
e: \(=\dfrac{-8}{56}-\dfrac{7}{56}=\dfrac{-15}{56}\)
f: \(=\dfrac{-5}{15}+\dfrac{3}{25}=\dfrac{-25}{75}+\dfrac{9}{75}=\dfrac{-16}{75}\)
TT
1
S
5 tháng 3 2023
Câu a :
\(\dfrac{5}{12}+\dfrac{3}{4}+\dfrac{1}{3}\\ =\dfrac{5}{12}+\dfrac{9}{12}+\dfrac{4}{12}=\dfrac{3}{2}\)
câu b :
\(\dfrac{1}{4}+\dfrac{3}{7}+\dfrac{11}{14}\\ =\dfrac{7}{28}+\dfrac{12}{28}+\dfrac{22}{28}=\dfrac{41}{28}\)
câu c :
\(\dfrac{1}{4}+\dfrac{3}{12}+\dfrac{12}{36}\\ =\dfrac{3}{12}+\dfrac{3}{12}+\dfrac{4}{12}\\ =\dfrac{10}{12}=\dfrac{5}{6}\)
TB
2
NT
3
5 tháng 3 2019
Sao cx gặp bài phân số không -_-
\(a)\frac{19}{21}-\frac{1}{3}+\frac{3}{7}=\frac{19}{21}-(\frac{1}{3}+\frac{3}{7})=\frac{19}{21}-\frac{16}{21}=\frac{3}{21}\)
\(b)1+\frac{2}{3}-\frac{5}{3}=\frac{3}{3}+\frac{2}{3}-\frac{5}{3}=\frac{5}{3}-\frac{5}{3}=0\)
\(c)\frac{7}{12}+\frac{1}{3}-\frac{3}{4}=\frac{7}{12}+\frac{4}{12}-\frac{9}{12}=\frac{7+4-9}{12}=\frac{2}{12}=\frac{1}{6}\)
\(d)\frac{5}{7}-\frac{4}{7}\cdot\frac{1}{4}=\frac{5}{7}-\frac{1}{7}=\frac{4}{7}\)
\(e)\frac{7}{12}\cdot\frac{4}{3}+\frac{2}{9}=\frac{7}{9}+\frac{2}{9}=\frac{9}{9}=1\)
5 tháng 3 2019
A. \(\frac{19}{21}-\frac{1}{3}+\frac{3}{7}=\frac{4}{7}+\frac{3}{7}=\frac{7}{7}=1\)
B. \(1+\frac{2}{3}-\frac{5}{3}=\frac{5}{3}-\frac{5}{3}=0\)
C. \(\frac{7}{12}+\frac{1}{3}-\frac{3}{4}=\frac{11}{12}-\frac{3}{4}=\frac{1}{6}\)
D. \(\frac{5}{7}-\frac{4}{7}\times\frac{1}{4}=\frac{5}{7}-\frac{1}{7}=\frac{4}{7}\)
E. \(\frac{7}{12}\times\frac{4}{3}+\frac{2}{9}=\frac{7}{9}+\frac{2}{9}=\frac{9}{9}=1\)
\(Linh\)\(Yukiko\)
22 tháng 2 2022
Bài 1:
a: -8/12<0<-3/-4
b: -56/24<0<7/3
c: 4/25<1<15/13
=>-4/25>-15/13
Bài 2:
a: =-60/45=-4/3
b: =4/15-3/2-8/5=8/30-45/30-48/30=-85/30=-17/6
NK
12 tháng 2 2023
\(a,\dfrac{4}{5}+\dfrac{2}{3}+\dfrac{1}{9}=\dfrac{12}{15}+\dfrac{10}{15}+\dfrac{1}{9}=\dfrac{22}{15}+\dfrac{1}{9}=\dfrac{66}{45}+\dfrac{5}{45}=\dfrac{71}{45}\)
\(b,\dfrac{3}{7}+\dfrac{11}{14}+\dfrac{19}{28}=\dfrac{12}{28}+\dfrac{22}{28}+\dfrac{19}{28}=\dfrac{53}{28}\)
\(c,\dfrac{1}{2}+\dfrac{1}{7}+\dfrac{-1}{5}=\dfrac{7}{14}+\dfrac{2}{14}+\dfrac{-1}{5}=\dfrac{9}{14}+\dfrac{-1}{5}=\dfrac{45}{70}+\dfrac{-14}{70}=\dfrac{31}{70}\)
\(d,\dfrac{7}{8}+\dfrac{5}{16}+\dfrac{-3}{4}=\dfrac{14}{16}+\dfrac{5}{16}+\dfrac{-12}{16}=\dfrac{7}{16}\)
\(e,\dfrac{1}{4}+\dfrac{5}{12}+\dfrac{-1}{13}=\dfrac{3}{12}+\dfrac{5}{12}+\dfrac{-1}{13}=\dfrac{8}{12}+\dfrac{-1}{13}=\dfrac{2}{3}+\dfrac{-1}{13}=\dfrac{26}{39}+\dfrac{-3}{39}=\dfrac{23}{39}\)
\(g,\dfrac{2}{3}+\dfrac{3}{8}+\dfrac{-5}{12}=\dfrac{16}{24}+\dfrac{9}{24}+\dfrac{-5}{12}=\dfrac{25}{24}+\dfrac{-5}{12}=\dfrac{25}{24}+\dfrac{-10}{24}=\dfrac{15}{24}\)
MH
2
AH
Akai Haruma
Giáo viên
10 tháng 9 2023
Lời giải:
a.
$\frac{7}{4}+\frac{5}{-6}+\frac{21}{8}=\frac{42}{24}+\frac{-20}{24}+\frac{63}{24}=\frac{85}{24}$
b.
$\frac{4}{9}+\frac{-7}{12}+\frac{8}{15}$
$=\frac{80}{180}+\frac{-105}{180}+\frac{96}{180}=\frac{71}{180}$
c.
$=\frac{-1}{3}+\frac{5}{6}+\frac{19}{12}+2$
$=\frac{-4}{12}+\frac{10}{12}+\frac{19}{12}+2=\frac{25}{12}+2=\frac{49}{12}$