Question

matematica clasa 6 Calculati: a) 2 supra 5-1 supra 10; b)5 supra 9-1 supra 3; c)3 supra 4-5 supra 8

Answer 1

Răspuns

$a) \frac{^{2)}2}{5}-\frac{1}{10}=\frac{2\cdot 2}{2\cdot5}-\frac{1}{10}=\frac{4}{10}-\frac{1}{10}=\frac{3}{10}\\ \\b)\frac{5}{9}-\frac{^{3)}1}{3}=\frac{5}{9}-\frac{3}{9}=\frac{2}{9}\\ \\c)\frac{3}{4}-\frac{5}{8}=\frac{^{2)}3}{4}-\frac{5}{8}=\frac{6}{8}-\frac{5}{8}=\frac{1}{8}$

Answer 2

$a) \frac{2}{5} - \frac{1}{10} = \frac{2}{5} - \frac{1}{2 \times 5} = \frac{2 \times 2 + ( - 1)}{5 \times 2} = \frac{4 - 1}{5 \times 2} = \frac{3}{10}$

$b) \frac{5}{9} - \frac{1}{3} = \frac{5}{ {3}^{2} } - \frac{1}{3} = \frac{5 + 3( - 1)}{ {3}^{2} } = \frac{5 - 3}{ {3}^{2} } = \frac{2}{9}$

$c) \frac{3}{4} - \frac{5}{8} = \frac{3}{ {2}^{2} } - \frac{5}{ {2}^{3} } = \frac{2 \times 3 + ( - 5)}{ {2}^{3} } = \frac{6 - 5}{ {2}^{3} } = \frac{1}{8}$