Ôn tập
1.Tính
130050:452 19183:78 204 \(\times\) 1942
2.Tính
\(\dfrac{4}{9}+\dfrac{3}{7}\) \(\dfrac{7}{15}-\dfrac{11}{30}\)
2 bạn đầu tiên xong .Mn trình bày rõ ràng cho e ạ cảm ơn!
K
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Những câu hỏi liên quan
13 tháng 3 2018
a, \(\dfrac{-4}{11}.\dfrac{7}{15}-\dfrac{4}{15}.\dfrac{8}{11}+\dfrac{-5}{11}\)
=\(\dfrac{-4}{11}.\dfrac{7}{15}+\dfrac{-4.8}{15.11}+\dfrac{-5}{11}\)
=\(\dfrac{-4}{11}.\dfrac{7}{15}+\dfrac{8}{15}.\dfrac{-4}{11}+\dfrac{-5}{11}\)
=\(\dfrac{-4}{11}.\left(\dfrac{7}{15}+\dfrac{8}{15}\right)+\dfrac{-5}{11}\)
=\(\dfrac{-4}{11}.1+\dfrac{-5}{11}\)
=\(\dfrac{-9}{11}\)
K
24 tháng 3 2022
\(a,\dfrac{7}{12}+\dfrac{3}{4}\times\dfrac{2}{9}=\dfrac{7}{12}+\dfrac{1}{6}=\dfrac{7}{12}+\dfrac{2}{12}=\dfrac{9}{12}=\dfrac{3}{4}\)
\(b,\dfrac{8}{9}-\dfrac{4}{15}:\dfrac{2}{5}=\dfrac{8}{9}-\dfrac{4}{15}\times\dfrac{5}{2}=\dfrac{8}{9}-\dfrac{2}{3}=\dfrac{8}{9}-\dfrac{6}{9}=\dfrac{2}{9}\)
ID
17 tháng 4 2022
a \(\dfrac{6}{15}+\dfrac{11}{15}=\dfrac{17}{15}\)
b \(\dfrac{22}{77}-\dfrac{14}{77}=\dfrac{8}{77}\)
c \(\dfrac{11}{13}\times\dfrac{26}{31}=11\times\dfrac{2}{31}=\dfrac{22}{31}\)
d \(\dfrac{1}{2}\times3\times\dfrac{2}{5}=\dfrac{3}{5}\)
MH
26 tháng 1 2022
\(A=\dfrac{-19}{9}.\dfrac{1}{2}-\dfrac{4}{11}.\dfrac{-11}{9}+\left(-\dfrac{2}{3}\right)=-\dfrac{23}{18}\)
\(B=\left(-\dfrac{15}{6}\right):\dfrac{-1}{2}+\dfrac{7}{-12}-\dfrac{1}{3}.\dfrac{-11}{2}=\dfrac{25}{4}\)
\(C=\dfrac{3}{4}.\left(-8\right)-\dfrac{1}{3}.\dfrac{-7}{2}-\dfrac{5}{18}=-\dfrac{46}{9}\)
26 tháng 1 2022
\(A=\dfrac{-19}{18}+\dfrac{4}{9}-\dfrac{2}{3}=\dfrac{-19}{18}+\dfrac{8}{18}-\dfrac{12}{18}=\dfrac{-23}{18}\)
\(B=\dfrac{-5}{2}\cdot\dfrac{-2}{1}-\dfrac{7}{12}+\dfrac{11}{6}=\dfrac{5\cdot12-7+22}{12}=\dfrac{75}{12}=\dfrac{25}{4}\)
7 tháng 2 2023
\(-\dfrac{3}{7}\times\dfrac{15}{13}-\dfrac{3}{7}\times\dfrac{11}{13}-\dfrac{3}{7}\)
\(=-\dfrac{3}{7}\left(\dfrac{15}{13}+\dfrac{11}{13}+1\right)\)
\(=-\dfrac{3}{7}\left(\dfrac{15}{13}+\dfrac{11}{13}+\dfrac{13}{13}\right)\)
\(=-\dfrac{3}{7}\times\dfrac{39}{13}=-\dfrac{3}{7}\times3=-\dfrac{9}{7}\)
12 tháng 7 2023
a: 4/9+3/7=28/63+27/63=55/63
3/4+7/24=18/24+7/24=25/24
1/3+2/9+4/27=9/27+6/27+4/27=19/27
b: 5/6-3/8=20/24-9/24=11/24
7/15-11/30=14/30-11/30=3/30=1/10
2/3+1/6-7/12
=8/12+2/12-7/12
=3/12=1/4
c: 18/25*15/6=15/25*18/6=3*3/5=9/5
30/49:6/7=30/49*7/6=210/294=5/7
1/2*3/4:6/5=3/8*5/6=15/48=5/16
d: 8*3/5:12/5=24/5*5/12=2
4:9/5:10/3=4*5/9*3/10=2/3
31 tháng 12 2022
a: =>x*2/15=2/7
=>x=2/7:2/15=2/7*15/2=15/7
b: x=3:7/5=15/7
c: x=-1/2:4/9=-1/2*9/4=-9/8
d: x=-8/3:3/8=-64/9
g: =>4/11x=2/5+1/3=6/15+5/15=11/15
=>x=11/15:4/11=121/60
l: =>1/4:x=1-3/2=-1/2
=>x=-1/4:1/2=-1/4*2=-1/2
k: =>x:7=-1/3+5/2=-2/6+15/6=13/6
=>x=91/6
Bài 1:
\(130050:452=287\)(dư 326)
\(19183:78=245\)(dư 73)
\(204\times1942=396168\)
Bài 2:
\(\dfrac{4}{9}+\dfrac{3}{7}=\dfrac{28}{63}+\dfrac{27}{63}=\dfrac{55}{63}\)
\(\dfrac{7}{15}-\dfrac{11}{30}=\dfrac{14}{30}-\dfrac{11}{30}=\dfrac{3}{30}=\dfrac{1}{10}\)