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\(4,7\div0,25+5,3\times4\)
\(=18,8+21,2\)
\(=40\)
\(3\times\left(a-2\right)+150=240\)
\(3\times\left(a-2\right)=90\)
\(a-2=30\)
\(a=32\)
\(\dfrac{1}{9}+a+\dfrac{7}{12}=\dfrac{17}{18}\)
\(\dfrac{1}{9}+a=\dfrac{13}{36}\)
\(a=\dfrac{1}{4}\)
\(\left(\dfrac{1}{2}\times\dfrac{1}{3}+\dfrac{1}{3}\times\dfrac{1}{4}+\dfrac{1}{4}\times\dfrac{1}{5}+\dfrac{1}{5}\times\dfrac{1}{6}+\dfrac{1}{6}\times\dfrac{1}{7}+\dfrac{1}{7}\times\dfrac{1}{8}\right)\times a=\dfrac{9}{16}\)
\(\left(\dfrac{1}{2\times3}+\dfrac{1}{3\times4}+\dfrac{1}{4\times5}+\dfrac{1}{5\times6}+\dfrac{1}{6\times7}+\dfrac{1}{7\times8}\right)\times a=\dfrac{9}{16}\)
\(\left(\dfrac{1}{2}-\dfrac{1}{8}\right)\times a=\dfrac{9}{16}\)
\(\dfrac{3}{8}\times a=\dfrac{9}{16}\)
\(a=\dfrac{3}{2}\)
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a: \(\dfrac{12}{7}\cdot\dfrac{3}{4}:\dfrac{3}{14}=\dfrac{36}{28}\cdot\dfrac{14}{3}=\dfrac{9}{7}\cdot\dfrac{14}{3}=\dfrac{9}{3}\cdot\dfrac{14}{7}=3\cdot2=6\)
b: 2+5/2:18
=2+5/36
=72/36+5/36
=77/36
\(\dfrac{12}{7}\times\dfrac{3}{4}:\dfrac{3}{14}\)
\(=\dfrac{12}{7}\times\dfrac{3}{4}\times\dfrac{14}{3}\)
\(=\dfrac{12\times3\times14}{7\times4\times3}\)
\(=\dfrac{3\times4\times7\times2\times3}{3\times4\times7}\)
\(=2\times3\)
\(=6\)
\(2+\dfrac{5}{2}:18\)
\(=2+\dfrac{5}{2}\times\dfrac{1}{18}\)
\(=2+\dfrac{5}{36}\)
\(=\dfrac{72}{36}+\dfrac{5}{36}\)
\(=\dfrac{77}{36}\)
#Toru
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a)\(x+\dfrac{2}{3}x\dfrac{5}{6}=7\)
\(x+\dfrac{10}{18}=7\)
\(x=7-\dfrac{10}{18}\)
\(x=\dfrac{58}{9}\)
b)\(9-xx\dfrac{1}{2}=\dfrac{3}{4}\)
\(xx\dfrac{1}{2}=9-\dfrac{3}{4}\)
\(xx\dfrac{1}{2}=\dfrac{33}{4}\)
\(x=\dfrac{33}{4}:\dfrac{1}{2}\)
\(x=\dfrac{33}{2}\)
c)\(18-x:\dfrac{2}{3}=\dfrac{4}{5}-\dfrac{1}{10}\)
\(18-x:\dfrac{2}{3}=\dfrac{7}{10}\)
\(x:\dfrac{2}{3}=18-\dfrac{7}{10}\)
\(x:\dfrac{2}{3}=\dfrac{173}{10}\)
\(x=\dfrac{173}{10}x\dfrac{2}{3}\)
\(x=\dfrac{173}{15}\)
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\(\Leftrightarrow4,5x-0,5x=2,6\)
\(\Leftrightarrow4x=2,6\)
\(\Leftrightarrow x=0,65\)
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Tính :
a )
145 + 637,38 : 18x 25
= 145 + 35,41 x 25
= 145 + 1593 , 45
= 1738,45
b) 456 + 50,5 : 2,5 x 0,125
= 456 + 20,2 x 0,125
= 456 + 2,525
= 458,525
tk mk nha
chắc chắn đúng luôn
ủng hộ mk nha !!!!!!!!!!
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\(x\cdot\dfrac{3}{7}-x\cdot\dfrac{1}{2}=\dfrac{3}{5}\)
\(x\left(\dfrac{3}{7}-\dfrac{1}{2}\right)=\dfrac{3}{5}\)
\(x\cdot\dfrac{-1}{14}=\dfrac{3}{5}\)
\(x=\dfrac{3}{5}:\dfrac{-1}{14}\)
\(x=\dfrac{-42}{5}\)
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Câu 1:
0,9 x 218 x 2 + 0,18 x 4290 + 0,6 x 353 x 3
= 9/10 x 436 + 9/50 x 4290 + 6/10 x 1059
= 9 x 43,6 + 9 x 85,8 + 6 x 105,9
= 3 x 130,8 + 3 x 257,4 + 3 x 211,8
= 3 x ( 130,8 + 257,4 + 211,8 )
= 3 x 600
= 1800
Câu 2:
3/4 x X + 1/2 x X - 15 = 35
X x ( 3/4 + 1/2 ) - 15 = 35
X x ( 3/4 + 1/2 ) = 50
X x 5/4 = 50
X = 40
VẬy X = 40
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\(\left(\frac{3}{4}+x\right).\frac{1}{2}=\frac{4}{5}\)
\(\frac{3}{4}+x=\frac{4}{5}:\frac{1}{2}\)
\(\frac{3}{4}+x=\frac{8}{5}\)
\(x=\frac{8}{5}-\frac{3}{4}\)
\(x=\frac{17}{20}\)
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\(43,57\times2,6\times(630-315\times2)\) mới đúng hay sao
\(=43,57\times2,6\times(630-630)\)
\(=43,57\times2,6\times0=0\)
1125 - 18 x X = 315
-18 x X = 315 - 1125
-18 x X = -810
X = -810 : -18
X = 45
( có cách khác nữa nhưng tui làm cách này )
18xX=1125-315
18xX=810
X=810:18
x=45