a) 4/15 + -7/12
b) 5/12 + -7/18
c) 7/36 - 5/24
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
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: \(=\dfrac{-5}{15}+\dfrac{3}{25}=\dfrac{-25}{75}+\dfrac{9}{75}=\dfrac{-16}{75}\)
TM
1
KV
5 tháng 1 2023
a) \(10-2\left(4-3x\right)=-4\)
\(2\left(4-3x\right)=10-\left(-4\right)\)
\(2\left(4-3x\right)=14\)
\(4-3x=\dfrac{14}{2}\)
\(4-3x=7\)
\(3x=4-7\)
\(3x=-3\)
\(x=-1\)
b) \(-12+3\left(-x+7\right)=-18\)
\(3\left(-x+7\right)=-18+12\)
\(3\left(-x+7\right)=-6\)
\(-x+7=-2\)
\(-x=-2-7\)
\(-x=-9\)
\(x=9\)
c) \(24:\left(3x-2\right)=-3\)
\(3x-2=24:\left(-3\right)\)
\(3x-2=-8\)
\(3x=-8+2\)
\(3x=-6\)
\(x=-2\)
d) \(-45:5\left(-3-2x\right)=3\)
\(5\left(-3-2x\right)=-45:3\)
\(5\left(-3-2x\right)=-15\)
\(-3-2x=-15:5\)
\(-3-2x=-3\)
\(-2x=-3+3\)
\(-2x=0\)
\(x=0\)
12 6 + 7 
12 4 + 7 
12
3 + 8 6 + 5 
6 + 6
L
3
22 tháng 6 2021
a) \(\dfrac{5}{24}+x=\dfrac{7}{12}\)
<=> \(x=\dfrac{7}{12}-\dfrac{5}{24}=\dfrac{14}{24}-\dfrac{5}{24}=\dfrac{9}{24}=\dfrac{3}{8}\)
b) \(x-\dfrac{3}{4}=\dfrac{1}{2}\)
<=> \(x=\dfrac{1}{2}+\dfrac{3}{4}=\dfrac{2}{4}+\dfrac{3}{4}=\dfrac{5}{4}\)
c) bn ghi rõ đề chút
NT
1
TA
5 tháng 4 2023
a) \(\dfrac{1}{9}\times\dfrac{4}{7}+\dfrac{1}{9}\times\dfrac{3}{7}=\dfrac{1}{9}\times\left(\dfrac{4}{7}+\dfrac{3}{7}\right)=\dfrac{1}{9}\times1=\dfrac{1}{9}\)
b) \(\dfrac{5}{13}\times\dfrac{189}{18}-\dfrac{5}{13}\times\dfrac{9}{18}=\dfrac{5}{13}\times\left(\dfrac{189}{18}-\dfrac{9}{18}\right)=\dfrac{5}{13}\times\dfrac{180}{18}=\dfrac{5}{13}\times10=\dfrac{50}{13}\)
c) \(\dfrac{12}{7}:\dfrac{4}{9}+\dfrac{4}{7}:\dfrac{4}{9}=\dfrac{12}{7}\times\dfrac{9}{4}+\dfrac{4}{7}\times\dfrac{9}{4}=\left(\dfrac{12}{7}+\dfrac{4}{7}\right)\times\dfrac{9}{4}=\dfrac{16}{7}\times\dfrac{9}{4}=\dfrac{144}{28}=\dfrac{36}{7}\)
NT
2
23 tháng 3 2022
\(a.\dfrac{6}{7}-\dfrac{4}{21}=\dfrac{18-4}{21}=\dfrac{14}{21}=\dfrac{2}{3}\\ b.6\times\dfrac{12}{18}=\dfrac{6\times12}{18}=\dfrac{4}{1}=4\\ c.\dfrac{2}{5}\times\dfrac{3}{7}+\dfrac{2}{5}\times\dfrac{4}{7}-\left(\dfrac{3}{7}+\dfrac{4}{7}\right)\times\dfrac{2}{5}=\dfrac{7}{7}\times\dfrac{2}{5}=1\times\dfrac{2}{5}=\dfrac{2}{5}\)
LK
1
ko hiểu................
a) 4/15 + (-7/12)
=16/60 + (- 35/60)
=(-19/60)
b) 5/12 + ( -7/18 )
= 15/36 + ( -14/36)
= 1/36
c) 7/36 - 5/24
= 14/72 + ( -15/72)
= (-1/72)