a)\(5^{2x-3}-2\cdot5^2=5^2\cdot3\)
\(5^{2x-3}-2\cdot25=75\)
\(5^{2x-3}-50=75\)
\(5^{2x-3}=125\)
\(125=5^3\)
\(5^3=5^{\left(3+3\right):2}=5^3\Rightarrow x=3\)
Vậy \(x=3\)
b)\(\frac{2}{9}\cdot\left(5x+1\right):2-\frac{1}{18}=\frac{5}{36}\)
\(=\frac{2}{9}\cdot\left(5x+1\right):2=\frac{5}{36}+\frac{1}{18}\)
\(=\frac{2}{9}\cdot\left(5x+1\right)=\frac{7}{36}\cdot2\)
\(5x+1=\frac{7}{18}:\frac{2}{9}\)
\(x=\left(\frac{7}{4}-1\right):5=\frac{3}{20}\)
\(\Rightarrow x=\frac{3}{20}\)
a, \(5^{2x-3}-2.5^2=5^2.3\)
\(\Leftrightarrow5^{2x-3}-2.25=25.3\)
\(\Leftrightarrow5^{2x-3}-50=75\)
\(\Leftrightarrow5^{2x-3}=125\)
\(\Leftrightarrow5^{2x-3}=5^3\)
\(\Leftrightarrow2x-3=3\)
\(\Leftrightarrow2x=6\)
\(\Leftrightarrow x=3\)
b, \(\frac{2}{9}.\left(5x+1\right):2-\frac{1}{18}=\frac{5}{36}\)
\(\Leftrightarrow\frac{2}{9}.\left(5x+1\right):2=\frac{7}{36}\)
\(\Leftrightarrow\frac{2}{9}.\left(5x+1\right)=\frac{7}{36}.2\)
\(\Leftrightarrow\frac{2}{9}.\left(5x+1\right)=\frac{7}{18}\)
\(\Leftrightarrow5x+1=\frac{7}{18}:\frac{2}{9}\)
\(\Leftrightarrow5x+1=\frac{7}{18}.\frac{9}{2}\)
\(\Leftrightarrow5x+1=\frac{7}{4}\)
\(\Leftrightarrow5x=\frac{3}{4}\)
\(\Leftrightarrow x=\frac{3}{4}:5=\frac{3}{4}.\frac{1}{5}=\frac{3}{20}\)
