Question

3 .Determinati opusul numarului rational a=5supra8 - 5supra9 x 0,3
4.Aflati rezultatul calculului (1supra2 -1supra3)totul la a 2 :0,25.
Cu explicatie daca se poate!

Answer 1

$\frac{5}{8} - \frac{5}{9}$ × 0,3=$\frac{5}{8} - \frac{5}{9}$ × $\frac{3}{10}$ $\frac{5}{8} - \frac{1}{3} × \frac{1}{2}$= $\frac{5}{8}- \frac{1}{6} = \frac{15}{24} - \frac{4}{24} = \frac{11}{24}$
11/24 x (-1)= -11/24

$(\frac{1}{2}- \frac{1}{3} )^{2} :0,25=( \frac{3}{6}- \frac{2}{6})^{2} : \frac{25}{100} = (\frac{1}{6})^{2} × \frac{100}{25}= \frac{1}{36} × \frac{100}{25}=$ $\frac{1}{9}  \frac{20}{25} = \frac{1}{9} × \frac{4}{5} = \frac{4}{45}$