№1 вычислите а) -4.9+ (-24.3)-(-5.1)-(+2.7)= б) -17.42 +(-6.83)-(-19.75)= в) (-3...

-4.9+(-24.3)-(-5.1)-2.7=-4.9-24.3+5.1-2.7=-31.9+5.1=26.8

-17.42+(-6.83)-(-19.75)=-17.42-6.83+19.75=-24.25+19.75=-4.5

$\\ (-3 \frac{8}{13})+(-1 \frac{4}{18})- \frac{9}{13}=- \frac{47}{13}- \frac{22}{18}- \frac{9}{13}= \frac{-846-286-162}{234}= \frac{-1294}{234}= \frac{-647}{117}= \\ =-5 \frac{62}{117}$

$\\ -(-5 \frac{1}{18} )-3 \frac{7}{9}+1 \frac{2}{3}= \frac{91}{18}- \frac{34}{9}+ \frac{5}{3}= \frac{182-136+60}{36}= \frac{106}{36}= \frac{53}{18}=2 \frac{17}{18}$