Question

(2/7.21/10)-1/2+(5/8.4)+4/3

Answer 1

2/7 . 21/10 = (simplifica cruzado)10 :2 e 21:7
Fica =  1/1 . 3/5 = 3/5
5/8 . 4 = 5/2 (simplificando)

$(\frac{2}{7}. \frac{21}{10})- \frac{1}{2}+ (\frac{5}{8}.4)+ \frac{4}{3}=$

$\frac{3}{5}- \frac{1}{2}+ \frac{5}{2}+ \frac{4}{3}=$

$\frac{3}{5}+ \frac{4}{2} + \frac{4}{3} =$ --mmc(2,3,5)=30

$\frac{18+60+40}{30} = \frac{118}{30}= \frac{59}{15}$