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a, x . 9,9 + x : 10 = 12,5
\(x.\frac{99}{10}+x.\frac{1}{10}=\frac{25}{2}\)
\(x\left(\frac{99}{10}+\frac{1}{10}\right)=\frac{25}{2}\)
\(x.10=\frac{25}{2}\)
\(x=\frac{25}{2}:10=\frac{25}{2}.\frac{1}{10}=\frac{5}{4}\)
b, \(x:\frac{1}{4}-x=\frac{78}{5}\)
\(x.4-x=\frac{78}{5}\)
\(x\left(4-1\right)=\frac{78}{5}\)
\(x.3=\frac{78}{5}\)
\(x=\frac{78}{5}:3=\frac{78}{5}.\frac{1}{3}=\frac{26}{5}\)
c, \(x:\frac{1}{10}-x:4-x.\frac{3}{4}=\frac{9}{4}\)
\(=x.10-x.\frac{1}{4}-x.\frac{3}{4}=\frac{9}{4}\)
\(x\left(10-\frac{1}{4}-\frac{3}{4}\right)=\frac{9}{4}\)
\(x.9=\frac{9}{4}\)
\(x=\frac{9}{4}:9=\frac{9}{4}.\frac{1}{9}=\frac{1}{4}\)
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\(x:0,25-x=15,6\)
\(x:\dfrac{1}{4}-x=15,6\)
\(x\text{×}4-x\text{×}1=15,6\)
\(x\text{×}\left(4-1\right)=15,6\)
\(x\text{×}3=15,6\)
\(x=15,6:3\)
\(x=5,2\)
x :0,25 -x=15,6
X x4 -x =15,6
X -1 x4 =15,6
X -4 =15,6
X=15,6+4
X=19,6
\(\text{X : 0,25 - X = 15,6}\)
\(x:\left(0,25-1\right)=15,6\)
\(x.\left(\frac{-3}{4}\right)=\frac{78}{5}\)
\(x=\frac{78}{5}:\left(\frac{-3}{4}\right)\)
\(x=-20,8\)
chúc bạn học tốt
\(x\div0,25-x=15,6\)
\(\Leftrightarrow\)\(x\div\frac{1}{4}-x=15,6\)
\(\Leftrightarrow\)\(x\times4-x=15,6\)
\(\Leftrightarrow\)\(x\times\left(4-1\right)=15,6\)
\(\Leftrightarrow\)\(x\times3=15,6\)
\(\Leftrightarrow\)\(x=15,6\div3\)
\(\Leftrightarrow\)\(x=5,2\)
x:0,25-x=15,6
x.4-x=15,6
x.(4-1)=15,6
x.3=15,6
x=15,6:3
x=5,2
\(x\div0,25-x=15,6\)
\(\Rightarrow\)\(x\div\frac{1}{4}-x=15,6\)
\(\Rightarrow\)\(x\times4-x=15,6\)
\(\Rightarrow\)\(x\times\left(4-1\right)=15,6\)
\(\Rightarrow\)\(x\times3=15,6\)
\(\Rightarrow\)\(x=15,6\div3\)
\(\Rightarrow\)\(x=5,2\)