Question

a ) -5/9+4/-9

b ) -5/39 -(34/39 +5 /-3)

Answer 1

a: \(\dfrac{-5}{9}+\dfrac{4}{-9}=\dfrac{-5}{9}+\dfrac{-4}{9}=\dfrac{-5-4}{9}=\dfrac{-9}{9}=-1\)

b: \(\dfrac{-5}{39}-\left(\dfrac{34}{39}+\dfrac{5}{-3}\right)\)

\(=\dfrac{-5}{39}-\dfrac{34}{39}+\dfrac{5}{3}\)

\(=-\dfrac{39}{39}+\dfrac{5}{3}=-1+\dfrac{5}{3}=\dfrac{2}{3}\)

Answer 2

Lời giải:
a. $\frac{-5}{9}+\frac{4}{-9}=\frac{-5}{9}+\frac{-4}{9}=\frac{-9}{9}=-1$

b. $\frac{-5}{39}-(\frac{34}{39}+\frac{5}{-3})=\frac{-5}{39}-\frac{34}{39}+\frac{5}{3}$
$=\frac{-39}{39}+\frac{5}{3}=-1+\frac{5}{3}=\frac{2}{3}$