X x 4/7 = 8/21
X:3/4=4/5
K
Khách
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S
27 tháng 11 2021
\(\dfrac{8}{9}+\dfrac{3}{18}=\dfrac{16}{18}+\dfrac{3}{18}=\dfrac{19}{18}\) \(\dfrac{5}{7}-\dfrac{4}{11}=\dfrac{55}{77}-\dfrac{28}{77}=\dfrac{3}{11}\)
\(\dfrac{3}{4}+\dfrac{4}{5}=\dfrac{15}{20}+\dfrac{16}{20}=\dfrac{21}{20}\) \(\dfrac{5}{7}-\dfrac{3}{5}=\dfrac{25}{35}-\dfrac{21}{35}=\dfrac{4}{35}\)
\(\dfrac{7}{9}X\dfrac{3}{4}=\dfrac{7}{9}X\dfrac{3}{4}=\dfrac{7}{12}\) \(\dfrac{8}{3}X\dfrac{21}{4}=\dfrac{8}{3}X\dfrac{21}{4}=14\)
\(\dfrac{12}{7}:\dfrac{1}{4}=\dfrac{12}{7}X\dfrac{4}{1}=\dfrac{48}{7}\) \(\dfrac{7}{2}:\dfrac{9}{4}=\dfrac{7}{2}X\dfrac{4}{9}=\dfrac{14}{9}\)
CM
26 tháng 2 2017
) 2 x 6 = 12 3 x 7 = 21
12 : 2 = 6 21 : 3 = 7
12 : 6 = 2 21 : 7 = 3
4 x 8 = 32 5 x 9 = 45
32 : 4 = 8 45 : 5 = 9
32 : 8 = 4 45 : 9 = 5
b) 600 : 3 = 200 800 : 4 = 200 400 : 2 = 200
600 : 2 = 300 800 : 2 = 400 500 : 5 = 100
LV
14 tháng 2 2021
a) 2x6=12 3x7=21
12:2=6 21:3=7
12:6=2 21:7=3
4x8=32 5x9=45
32:4=8 45:5=9
32:8=4 45:9=5
b) 600:3=200 800:4=200 400:2=200
600:2=300 800:2=400 500:5=100
A Legend Never Dies
27 tháng 1 2023
\(a.\dfrac{6}{5}=\dfrac{18}{x}\Rightarrow x=\dfrac{18\cdot5}{6}=15\\ \text{Vậy}\text{ }x=15.\)
\(b.\dfrac{3}{4}=\dfrac{-21}{x}\Rightarrow x=\dfrac{-21\cdot4}{3}=28\\ \text{ }\text{ }\text{ }\text{ }\text{Vậy }x=28.\)
\(c.\dfrac{x}{4}=\dfrac{21}{28}\Rightarrow x=\dfrac{21\cdot4}{28}=3\\ \text{Vậy }x=3.\)
\(d.\dfrac{-8}{2x}=\dfrac{3}{-9}\Rightarrow x=\dfrac{-8\cdot\left(-9\right)}{3}:2=12\\ \text{Vậy }x=12.\)
\(e.\dfrac{-4}{11}=\dfrac{x}{22}=\dfrac{40}{z}\\ \Rightarrow x=\dfrac{-4\cdot22}{11}=-8\\ \Rightarrow z=\dfrac{22\cdot40}{-8}=-110\\ \text{Vậy }x=-8;z=-110.\)
\(f.\dfrac{-3}{4}=\dfrac{x}{20}=\dfrac{21}{y}\\ \Rightarrow x=\dfrac{-3\cdot20}{4}=-15\\ \Rightarrow y=\dfrac{21\cdot20}{-15}=-28\\ \text{Vậy }x=-15;y=-28.\)
\(g.\dfrac{-4}{8}=\dfrac{x}{-10}=\dfrac{-7}{y}=\dfrac{z}{-24}\\ \Rightarrow x=\dfrac{-4\cdot\left(-10\right)}{8}=5\\ \Rightarrow y=\dfrac{-7\cdot\left(-10\right)}{5}=14\\ \Rightarrow z=\dfrac{-7\cdot\left(-24\right)}{14}=12\\ \text{Vậy }x=5;y=14;z=12.\)
\(h.\dfrac{x}{4}=\dfrac{9}{x}\\ \Rightarrow x\cdot x=9\cdot4\\ \Rightarrow x\cdot x=36\\ \Rightarrow x\cdot x=6\cdot6\\ \text{Vậy }\text{cả hai }x=6.\)
5 tháng 11 2021
có rút gọn phân số 35/6 về phân số đc ko ? Nếu có thì mn rút gọn cho mik nhé !
Ai xong tr tui k cho
18 tháng 3 2023
\(a,\dfrac{4}{5}+\dfrac{2}{7}=\dfrac{28}{35}+\dfrac{10}{35}=\dfrac{38}{35}.\)
\(b,2-\dfrac{8}{9}=\dfrac{18}{9}-\dfrac{8}{9}=\dfrac{10}{9}.\)
\(c,\dfrac{5}{8}\times3=\dfrac{5\times3}{8}=\dfrac{15}{8}.\)
\(d,5:\dfrac{6}{21}=5\times\dfrac{21}{6}=\dfrac{5\times21}{6}=\dfrac{105}{6}=\dfrac{35}{2}.\)
\(đ,\dfrac{3}{5}\times\dfrac{4}{5}\times\dfrac{6}{7}=\dfrac{3\times4\times6}{5\times5\times7}=\dfrac{72}{175}.\)
Y
18 tháng 3 2023
\(a,\dfrac{4}{5}+\dfrac{2}{7}=\dfrac{28}{35}+\dfrac{10}{35}=\dfrac{38}{35}\)
\(b,2-\dfrac{8}{9}=\dfrac{18}{9}-\dfrac{8}{9}=\dfrac{10}{9}\)
\(c,\dfrac{5}{8}\times3=\dfrac{5\times3}{8\times1}=\dfrac{15}{8}\)
\(d,\dfrac{3}{5}\times\dfrac{4}{5}\times\dfrac{6}{7}=\dfrac{3\times4\times6}{5\times5\times7}=\dfrac{72}{175}\)
24 tháng 2 2022
\(\dfrac{26}{81}+\dfrac{4}{27}=\dfrac{26+12}{81}=\dfrac{38}{81}\)
\(\dfrac{5}{64}+\dfrac{7}{8}=\dfrac{5+56}{64}=\dfrac{61}{64}\)
24 tháng 2 2022
\(\dfrac{26}{81}+\dfrac{4}{27}=\dfrac{26}{81}+\dfrac{4\times3}{27\times3}=\dfrac{26}{81}+\dfrac{12}{81}=\dfrac{38}{81}\)
\(\dfrac{5}{64}+\dfrac{7}{8}=\dfrac{5}{64}+\dfrac{7\times8}{8\times8}=\dfrac{5}{64}+\dfrac{56}{64}=\dfrac{61}{64}\)
20 tháng 5 2022
2/3 + 3/4=17/12
9/4 + 3/5=57/20
5/24 + 1/4=11/24
3/15 - 5/35=2/35 18/27 - 2/6=1/3 37/12 - 3=1/12
11/9 x 3/22=1/6 7/13 x 13/7=1 4 x6/7=24/7
2/5 : 3/10=4/3 3/8 : 9/4=1/6 8/21 : 4/7=2/3
X = 8/21 : 4/7
X= 2/3
X = 4/5 x 3/4
X=3/5
`x xx 4/7 = 8/21`
`x = 8/21 : 4/7`
`x = 2/147`
____________________
`x : 3/4 = 4/5`
`x = 4/5 xx 3/4`
`x= 3/5`