Question

Calculati, folosind proprietatile adunarii:
a) 15pe14 + 4pe7 + 17pe14=?
b) 14pe15 + 2pe5 + 13pe15=?
d) 23pe25 + 6pe5 + 17pe25 =?
e) 31pe27 + 8pe3 + 14pe27=?
Va rog ajutatima = MULȚUMESC!

Answer 1

$a) \frac{15}{14} + \frac{4}{7} + \frac{17}{14} = (\frac{15}{14} + \frac{17}{14}) + \frac{4}{7} = \frac{15 + 17 }{14} + \frac{4}{7} = \frac{32}{14} + \frac{4}{7} = \frac{16}{7} + \frac{4}{7} = \frac{16 + 4}{7} = \frac{20}{7}$

$b) \frac{14}{15} + \frac{2}{5} + \frac{13}{15} = (\frac{14}{15} + \frac{13}{15} )+ \frac{2}{5} = \frac{14 + 13}{15} + \frac{2}{5} = \frac{27}{15} + \frac{2}{5} = \frac{9}{5} + \frac{2}{5} = \frac{9 + 2}{5} = \frac{11}{5}$

$c) \frac{23}{25} + \frac{6}{5} + \frac{17}{25} = (\frac{23}{25} + \frac{17}{25}) + \frac{6}{5} = \frac{23 + 17}{25} + \frac{6}{5} = \frac{40}{25} + \frac{6}{5} = \frac{8}{5} + \frac{6}{5} = \frac{8 + 6 }{5} = \frac{14}{5}$

$d) \frac{31}{27} + \frac{8}{3} + \frac{14}{27} = (\frac{31}{27} + \frac{14}{27}) + \frac{8}{3} = \frac{31 + 14}{27} + \frac{8}{3} = \frac{45}{27} + \frac{8}{3} = \frac{5}{3} + \frac{8}{3} = \frac{5 + 8}{3} = \frac{13}{3}$