a ) \(\frac{3}{8}+\left(x-\frac{5}{24}\right):\frac{2}{3}=1\) | \(\left(x-\frac{5}{24}\right):\frac{2}{3}=1-\frac{3}{8}=\frac{5}{8}\)
\(x-\frac{5}{24}=\frac{5}{8}\times\frac{2}{3}=\frac{10}{24}=\frac{5}{12}\) | \(x=\frac{5}{12}+\frac{5}{24}=\frac{15}{24}=\frac{5}{8}\)
b ) \(125\div x+375\div x-200\div x=12\)
\(\frac{125}{x}+\frac{375}{x}-\frac{200}{x}=12=\frac{300}{x}\)
\(x=300\div12=25\)