│x + 5 │= 21
Những câu hỏi liên quan
Tính nhanh : 9/15 x 5/21 + 29/21 x 2/5 + 9/5 x 8/21
các bạn làm đủ bước nhé.
21-x/21+27-x/225-x/25+23-x/27+21-x/29=-5
Tính giá trị biểu thức:
A=-5.x/21+-5.y/21+-5/21 biết x+y=-z
15 tháng 5 2022 lúc 9:13
\(\dfrac{22}{5}\) x \(\dfrac{21}{22}\) x \(\dfrac{5}{21}\)
\(\dfrac{22}{5}\) x \(\dfrac{21}{22}\) x \(\dfrac{5}{21}\)
= \(\dfrac{5}{5}\) = 1
Tick cho mik nha
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24 tháng 2 2022 lúc 16:10
Tính theo mẫu :
Mẫu : 13/21 + 5/7 = 13/21 + 5 x 3 / 7 x 3 = 13/21 + 15/21 = 28/21
26/81 + 4/27
5/64 + 7/8
\(\dfrac{26}{81}+\dfrac{4}{27}=\dfrac{26+12}{81}=\dfrac{38}{81}\)
\(\dfrac{5}{64}+\dfrac{7}{8}=\dfrac{5+56}{64}=\dfrac{61}{64}\)
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\(\dfrac{26}{81}+\dfrac{4}{27}=\dfrac{26}{81}+\dfrac{4\times3}{27\times3}=\dfrac{26}{81}+\dfrac{12}{81}=\dfrac{38}{81}\)
\(\dfrac{5}{64}+\dfrac{7}{8}=\dfrac{5}{64}+\dfrac{7\times8}{8\times8}=\dfrac{5}{64}+\dfrac{56}{64}=\dfrac{61}{64}\)
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TÍNH THUẬN TIỆN
\(\dfrac{21}{5}\) X 13 X \(\dfrac{5}{21}\)
\(\left(\dfrac{21}{5}\times\dfrac{5}{21}\right)\times13=1\times13=13\)
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\(\dfrac{29-x}{21}\)+\(\dfrac{27-x}{23}\)+\(\dfrac{25-x}{25}\)+\(\dfrac{23-x}{27}\)+\(\dfrac{21-x}{29}\)=\(\dfrac{(29-x+1}{21}\)+\(\dfrac{(27-x+1)}{23}\)+\(\dfrac{(25-x+1)}{25}\)+\(\dfrac{(23-x+1)}{21}\)=-5 +5
GIẢI nốt hộ mình với ạ
Tìm x
121-5×(60-5×x)=2110÷(216×213)
\(121-5.\left(60-5x\right)=21^{10}:\left(21^6.21^3\right)\)
\(121-5.\left(60-5x\right)=21^{10}:21^9\)
\(121-5.\left(60-5x\right)=21\)
\(5.\left(60-5x\right)=121-21\)
\(5.\left(60-5x\right)=100\)
\(60-5x=100:5\)
\(60-5x=20\)
\(5x=60-20\)
\(5x=20\)
\(\Rightarrow x=4\)
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\(121-5.\left(60-5x\right)=21^{10}:\left(21^6.21^3\right)\)
\(121-300+25x=21^{10}:21^{11}\)
\(25x-179=\frac{1}{21}\)
\(25x=\frac{1}{21}+179\)
\(25x=\frac{3760}{21}\)
\(x=\frac{3760}{21}:25\)
\(x=\frac{752}{105}\)
vay \(x=\frac{752}{105}\)
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a) ( 21/22 + 3/5 + -21/22 ) : 1 2/5 9/17 x 8/5 - 9/17 x 3/5 + 8/17
X - 3/10 = 7/15 x 3/15
a: \(=\dfrac{3}{5}:\dfrac{7}{5}=\dfrac{3}{5}\cdot\dfrac{5}{7}=\dfrac{3}{7}\)
b: \(=\dfrac{9}{17}\left(\dfrac{8}{5}-\dfrac{3}{5}\right)+\dfrac{8}{17}\)
=9/17+8/17=1
c: =>x-3/10=7/15*1/5=7/75
=>x=7/75+3/10=59/150
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tinh bang hai cach
3/5 x 7/21 + 7/21 x 2/5
\(\frac{3}{5}\times\frac{7}{21}+\frac{7}{21}\times\frac{2}{5}=\frac{7}{21}\times\left(\frac{3}{5}+\frac{2}{5}\right)=\frac{1}{3}\times\left(\frac{3}{5}+\frac{2}{5}\right)=\frac{1}{3}\times1=\frac{1}{3}\)
Học tốt !
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\(\frac{3}{5}\cdot\frac{7}{21}+\frac{7}{21}+\frac{2}{5}\)
\(=\frac{7}{21}\cdot(\frac{3}{5}+\frac{2}{5})\)
\(=\frac{7}{21}\cdot1=\frac{7}{21}=\frac{1}{3}\)
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C1 \(\frac{3}{5}.\frac{7}{21}+\frac{7}{21}.\frac{2}{5}\)
\(=\frac{7}{21}\left(\frac{3}{5}+\frac{2}{5}\right)\)
\(=\frac{7}{21}.1\)
\(=\frac{7}{21}=\frac{1}{3}\)
C2 \(\frac{3}{5}.\frac{7}{21}+\frac{7}{21}.\frac{2}{5}\)
\(=\frac{3.7}{5.21}+\frac{7.2}{21.5}\)
\(=\frac{21}{105}+\frac{14}{105}\)
\(=\frac{35}{105}\)
\(=\frac{7}{21}=\frac{1}{3}\)
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