Răspuns:
[tex]\boxed{\boxed{\bf \dfrac{8}{21}-\dfrac{4}{35} = \dfrac{4}{15} }}[/tex]
Explicație pas cu pas:
[tex]\bf 21=3 \cdot 7[/tex]
[tex]\bf 35 = 5 \cdot 7[/tex]
[tex]\bf \implies\bigg [21;35\bigg]= 3 \cdot 5 \cdot 7 = 105[/tex]
[tex]\bf 105 : 21 = 5 \implies amplificam\; \dfrac{8}{21} \; cu \; 5 = \dfrac{40}{105}[/tex]
[tex]\bf 105:35 = 3 \implies amplificam \; \dfrac{4}{35}\; cu \; 3 = \dfrac{12}{105}[/tex]
[tex]\bf \dfrac{8}{21} -\dfrac{4}{35} = \dfrac{40}{105} - \dfrac{12}{105 } = \dfrac{40-12}{105}= \dfrac{28}{105} ^{(7} = \boxed{\bf \dfrac{4}{15} }[/tex]
#copaceibrainly
