Question

Алгебра! Срочно нужно! Даю 30 баллов!

Answer 1

Объяснение:

• 1.

$frac{21}{5} div frac{6}{7} = frac{21 times 7}{5 times 6} = frac{7 times 7}{5 times 2} = frac{49}{10} = 4.9$

• 2.

$frac{3}{5} div frac{4}{35} = frac{3 times 35}{5 times 4} = frac{3 times 7}{4} = frac{21}{4} = 5 frac{1}{4} = 5.25$

• 3.

$frac{4}{5} div frac{2}{7} = frac{4 times 7}{5 times 2} = frac{14}{5} = 2 frac{4}{5} = 2.8$

• 4.

$frac{21}{2} div frac{3}{5 } = frac{21 times 5}{2 times 3} = frac{35}{2} = 17 frac{1}{2} = 17.5$

• 5.

$frac{3}{4} + frac{7}{25} = frac{3 times 25 + 7 times 4}{100} = frac{75 + 28}{100} = frac{103}{100} = 1 frac{3}{100} = 1.03$

• 6.

$frac{9}{4} + frac{8}{5} = 2 frac{1}{4} + 1 frac{3}{5} = 3 frac{5 + 12}{20} = 3 frac{17}{20} = 3.85$

• 7.

$frac{11}{5} + frac{13}{4} = 2 frac{1}{5} + 3 frac{1}{4} = 5 frac{4 + 5}{20} = 5 frac{9}{20} = 5.45$