Question

Scrieti folosind paranteze,apoi calculati: a)Din suma fractiilor 18 intreg 3/4 si 16 intreg 3/5 scadeti diferenta fractiilor 25 intreg 5/8 si 17 intreg 7/10.

Answer 1

$(18\frac{3}{4} + 16\frac{3}{5})$ - $(25\frac{5}{8} - 17\frac{7}{10})$ = $(\frac{4 X 18 + 3}{4} + \frac{5 X 16 + 3}{5})$ - $(\frac{8 X 25 + 5}{8} - \frac{10 X 17 + 7}{10})$ = $(\frac{75}{4} + \frac{83}{5})$ - $(\frac{205}{8} - \frac{177}{10})$ =

$\frac{75}{4}$ amplificam cu 5 = $\frac{75 X 5}{4 X 5}$ = $\frac{375}{20}$
$\frac{83}{5}$ amplificam cu 4 = $\frac{83 X 4}{5 X 4}$ = $\frac{332}{20}$
$\frac{205}{8}$ amplificam cu 5 = $\frac{205 X 5}{8 X 5}$ = $\frac{1025}{40}$
$\frac{177}{10}$ amplificam cu 4 = $\frac{177 X 4}{10 X 4}$ = $\frac{708}{40}$

$(\frac{375}{20} + \frac{332}{20})$ - $(\frac{1025}{40} - \frac{708}{40})$ = $\frac{375 + 332}{20} - \frac{1025 - 708}{40}$ = $\frac{707}{20} - \frac{317}{40}$ =

$\frac{707}{20}$ amplificam cu 2 = $\frac{707 X 2}{20 X 2}$ = $\frac{1414}{40}$
iar $\frac{317}{40}$ lasam asa.

$\frac{1414}{40}$ - $\frac{317}{40}$ = $\frac{1414 - 317}{40}$ = $\frac{1097}{40}$ = 27,425