Question

Calcule 2/3: (1-0,25)+1/2× (2/3 -0,75)

Answer 1

$\ \ \ \frac{2}{3} : (1-0,25)+ \frac{1}{2}\times \big( \frac{2}{3} -0,75\big)\\ \\= \frac{2}{3} : \big(1-\frac{1}{4}\big)+ \frac{1}{2}\times \big( \frac{2}{3} -\frac{3}{4}\big)\\ \\= \frac{2}{3} : \big(\frac{4}{4}-\frac{1}{4}\big)+ \frac{1}{2}\times \big( \frac{8}{12} -\frac{9}{12}\big)\\ \\= \frac{2}{3} : \frac{3}{4}+ \frac{1}{2}\times \big(-\frac{1}{12}\big)\\ \\= \frac{2}{3} \cdot \frac{4}{3}-\frac{1}{24}\\ \\= \frac{8}{9}-\frac{1}{24}\\ \\= \frac{64}{72}-\frac{3}{72}\\ \\= \frac{61}{72}$