Question

calculati: 2 1/2×12/25; 4 1/3×21/26; 7 3/5×15/19; 2 2/5×25/12​

Answer 1

Răspuns:

• $\frac{6}{5}$
• $\frac{7}{2}$
• $6$
• $5$

Explicație pas cu pas:

$2 \frac{1}{2} \times \frac{12}{25} = \frac{2 \times 2 + 1}{2} \times \frac{12}{25} \\ = ( 4 + 1) \times \frac{6}{25} \\ = 5 \times \frac{6}{25} \\ = \frac{6}{5}$

$4 \frac{1}{3} \times \frac{21}{26} = \frac{4 \times 3 + 1}{3} \times \frac{21}{26} \\ = (12 + 1) \times \frac{7}{26} \\ = 13 \times \frac{7}{26} \\ = \frac{7}{2}$

$7 \frac{3}{5} \times \frac{15}{19} = \frac{7 \times 5 + 3}{5} \times \frac{15}{19} \\ = (35 + 3) \times \frac{3}{19} \\ = 38 \times \frac{3}{19} \\ = 2 \times 3 \\ = 6$

$2 \frac{2}{5} \times \frac{25}{12} = \frac{2 \times 5 + 2}{5} \times \frac{25}{12} \\ = ( 10 + 2) \times \frac{5}{12} \\ = 12 \times \frac{5}{12} \\ = 5$