Giải bài 3 trang 16 toán 7 tập 1 chân trời sáng tạo.

a) $\left( \frac{-5}{8} \right)$ + $\left( \frac{3}{-8} \right)$ =$\left( \frac{-5}{8} \right)$ + $\left( \frac{-3}{8} \right)$-1

b) $\frac{-8}{11}$ > $\left( \frac{-13}{22} \right)$ + $\left( \frac{-5}{22} \right)$

 ( vì $\left( \frac{-13}{22} \right)$ + $\left( \frac{-5}{22} \right)$ = $\left( \frac{-9}{11} \right)$; mà $\left( \frac{-8}{11} \right)$ > $\left( \frac{-9}{11} \right)$ )

c) $\frac{1}{6}$ + $\left( \frac{-3}{4} \right)$ < $\frac{1}{14}$ + $\left( \frac{-4}{7} \right)$

( vì $\frac{1}{6}$ + $\left( \frac{-3}{4} \right)$ = $\left( \frac{-7}{12} \right)$ ;  $\frac{1}{14}$ + $\left( \frac{-4}{7} \right)$ = $\left( \frac{-1}{2} \right)=\frac{-6}{12}$ ; mà  $\left( \frac{-7}{12} \right)$ < $\left( \frac{-1}{2} \right)$ )