Răspuns: [tex]\color{red} \Large\boxed{\bf \dfrac{631}{40}}~~sau~~\Large\boxed{\bf 15\dfrac{31}{40}}[/tex]
[tex]\large \bf 6\dfrac{7}{8}+ 8\dfrac{9}{10}=\dfrac{6\cdot 8+7}{8} +\dfrac{8\cdot10+9}{10} =\dfrac{55}{8}+ \dfrac{89}{10}=[/tex]
[tex]\large \bf \dfrac{55\cdot5}{8\cdot5}+ \dfrac{89\cdot 4}{10\cdot 4}=\dfrac{275}{40}+ \dfrac{356}{40}=\Large\boxed{\bf \dfrac{631}{40}}~~sau~~\Large\boxed{\bf 15\dfrac{31}{40}}[/tex]
[tex]\large \bf 6\dfrac{7}{8}+ 8\dfrac{9}{10}=(6+8)+\bigg(\dfrac{7}{8} +\dfrac{9}{10}\bigg) =14+\bigg(\dfrac{7\cdot5}{8\cdot5} +\dfrac{9\cdot4}{10\cdot4}\bigg) =[/tex]
[tex]\large \bf 14+\bigg(\dfrac{35}{40} +\dfrac{36}{40}\bigg) = 14+\dfrac{71}{40} = 14+1\dfrac{31}{40} =14+1+ \dfrac{31}{40}=\Large\boxed{\bf 15\dfrac{31}{40} }[/tex]
Bafta multa!
PS: Daca esti pe telefon, te rog sa glisezi spre stânga pentru a vedea rezolvarea completa.
==pav38==
