Question

Doar ex9 dau coronița si multe puncte

Answer 1

Rezolvare :
$a) \frac{3}{7} \times 77 + \frac{2}{5} \times 77 = 3 \times 11 + \frac{154}{5} = 33 + \frac{154}{5} = \frac{319}{5}$
$b)3 \times 5 + 3 \times \frac{1}{4} + 3 \times \frac{17}{16} = 15 + \frac{3}{4} + \frac{51}{16} = \frac{303}{16}$
$c) \frac{2}{5} \times 7 + 3 \times 7 - 7 \times \frac{12}{5} = \frac{14}{5} + 21 - \frac{84}{5} = 7$
$d) \frac{3}{19} \times \frac{3}{7} + \frac{3}{19} \times \frac{4}{7} = \frac{9}{133} + \frac{12}{133} = \frac{3}{19}$
$e) \frac{2}{23 } \times \frac{3}{5} - \frac{2}{5} \times \frac{3}{46} = \frac{6}{155} - \frac{2}{5} \times \frac{1}{12} = \frac{6}{115} - \frac{1}{5} \times \frac{1}{6} = \frac{6}{115} - \frac{1}{30} = \frac{13}{690}$
$f)5 \times \frac{5}{11} + 5 \times \frac{3}{22} - 5 \times \frac{1}{2} = \frac{35}{11} + \frac{15}{22} - \frac{5}{2} = \frac{15}{11}$