1/5 + 3/5 2/3 . 2/7 -2/3 . 3/7 +8/7 . 2/3 -3/5+7/13+-2/5+ -23/25 + 6/13 (1/3+3/4 -13/12):(12/23+123/234+1234/2345)

a, $\frac{1}{5}$ + $\frac{3}{5}$ 

= $\frac{1+3}{5}$ = $\frac{4}{5}$ 

b. $\frac{2}{3}$ . $\frac{2}{7}$ – $\frac{2}{3}$ . $\frac{3}{7}$ + $\frac{8}{7}$ . $\frac{2}{3}$ 

= $\frac{2}{3}$ . ($\frac{2}{7}$ – $\frac{3}{7}$+ $\frac{8}{7}$)

= $\frac{2}{3}$ . 1 = $\frac{2}{3}$

c. $\frac{-3}{5}$ + $\frac{7}{13}$ + $\frac{-2}{5}$+ $\frac{-23}{25}$ + $\frac{6}{13}$

= ($\frac{-3}{5}$ + $\frac{-2}{5}$) + ($\frac{7}{13}$+ $\frac{6}{13}$)+ $\frac{-23}{25}$

= -1 + 1 + $\frac{-23}{25}$

= 0 + $\frac{-23}{25}$

= $\frac{-23}{25}$

d. (1/3+3/4 -13/12):(12/23+123/234+1234/2345)

= (4/12 + 9/12 – 13/12) : (12/23+123/234+1234/2345)

= 0: (12/23+123/234+1234/2345)

= 0