Răspuns:
Explicație pas cu pas:
[tex]\large \bf a)~~\dfrac{4}{5}-\dfrac{\boxed{}}{10}=\dfrac{7}{10}[/tex]
[tex]\large \bf \dfrac{4\cdot 2}{5\cdot 2}-\dfrac{\boxed{}}{10}=\dfrac{7}{10}[/tex]
[tex]\large \bf \dfrac{8}{10}-\dfrac{\boxed{}}{10}=\dfrac{7}{10}[/tex]
[tex]\large \bf \dfrac{8}{10}=\dfrac{7}{10} +\dfrac{\boxed{}}{10}[/tex]
[tex]\large \bf \dfrac{8}{10}-\dfrac{7}{10} =\dfrac{\boxed{}}{10}[/tex]
[tex]\large \bf \dfrac{1}{10}=\dfrac{\boxed{}}{10}[/tex]
[tex]\large \bf 1 \cdot 10=\boxed{}\cdot 10~~~\bigg|:10[/tex]
[tex]\color{red}\Large \bf \boxed{\bf \boxed{}=1}[/tex]
[tex]\it~~[/tex]
[tex]\large \bf b)~~\dfrac{5}{\boxed{}}+ \dfrac{4}{3}=\dfrac{17}{9}[/tex]
[tex]\large \bf ~\dfrac{5}{\boxed{}}+ \dfrac{4\cdot 3}{3\cdot 3}=\dfrac{17}{9}[/tex]
[tex]\large \bf ~\dfrac{5}{\boxed{}}+ \dfrac{12}{9}=\dfrac{17}{9}[/tex]
[tex]\large \bf ~\dfrac{5}{\boxed{}}=\dfrac{17}{9} - \dfrac{12}{9}[/tex]
[tex]\large \bf ~\dfrac{5}{\boxed{}}=\dfrac{5}{9} \implies5\cdot \boxed{} = 5\cdot 9[/tex]
[tex]\large \bf 5\cdot \boxed{} = 45 ~~~~\bigg|:5[/tex]
[tex]\color{red}\Large \bf \boxed{\bf \boxed{}=9}[/tex]
==pav38==
