Răspuns:
Explicație pas cu pas:
a)
[tex]\frac{x}{12} = \frac{\frac{7}{12} }{7}[/tex]
[tex]\frac{x}{12} = \frac{1}{12}[/tex]
X=1
b)
[tex]\frac{1}{5}-\frac{1}{5}*\frac{1}{5}=\frac{1}{5}-\frac{1}{25} =\frac{4}{25}[/tex][tex]\frac{1}{25}=\frac{x}{75} => x=\frac{75}{25}=3[/tex]
