`a)` `(-5)/11 + ((-6)/11 + 1)`

`= (-5)/11 + (-6)/11 + 1`

`= (-1) + 1`

`= 0`

`b)` `3/4 . 7/25 + 3/4 . 18/25`

`= 3/4 . (7/25 + 18/25)`

`= 3/4 . 1`

`= 3/4`

`c)` `7/5 . 8/19 + 7/5 . 12/19 - 7/5 . 1/19`

`= 7/5 . (8/19 + 12/19 - 1/19)`

`= 7/5 . 1`

`= 7/5`

$\textit{* ChieyewCucCuk}$

$\textit{Đáp án:}$

$\textit{a) 0}$

$\textit{b)}$ $\dfrac{3}{4}$

$\textit{c)}$ $\dfrac{7}{5}$

$\textit{Giải thích các bước giải:}$

a) $\dfrac{-5}{11}$ + ( $\dfrac{-6}{11}$ + 1 ) 

= ( $\dfrac{-5}{11}$ +  $\dfrac{-6}{11}$ ) + 1 

=                        ( - 1 )                            + 1 

=                                   0

b)  $\dfrac{3}{4}$ .  $\dfrac{7}{25}$ + $\dfrac{3}{4}$ . $\dfrac{18}{25}$ 

= $\dfrac{3}{4}$ . ( $\dfrac{7}{25}$ $\dfrac{18}{25}$ )

= $\dfrac{3}{4}$ .          1

=            $\dfrac{3}{4}$

c) $\dfrac{7}{5}$ . $\dfrac{8}{19}$ + $\dfrac{7}{5}$ . $\dfrac{12}{19}$ - $\dfrac{7}{5}$ . $\dfrac{1}{19}$

= $\dfrac{7}{5}$ . ( $\dfrac{8}{19}$ + $\dfrac{12}{19}$ - $\dfrac{1}{19}$ )

= $\dfrac{7}{5}$ .                  1

=                    $\dfrac{7}{5}$

                                    $\textit{- #Chúcbạnhọctốt! -}$