Tính

1.Tính :

$a, \frac{-4}{13} + \frac{3}{19} + \frac{-9}{13} + \frac{16}{19} + \frac{2013}{2014} .$
 $b, \frac{-4}{15 } : \frac{-8}{45} + {\left(\frac{-3}{2}\right)}^2 . \frac{-2}{27} + \frac{-4}{9} .$
$c, \frac{-13}{14} . \frac{45}{51} + \frac{-13}{14} . \frac{6}{51} + 1\frac{13}{14} .$
$d, \frac{2}{7.11} + \frac{2}{11.15} + \frac{2}{15.19} +...+ \frac{2}{91.95} .$​ 
2. Tìm x, biết :
$a, x-\frac{3}{7} = \frac{1}{2} .$
$b,\frac{11}{13} - \frac{3}{13} . x = \frac{3}{26} .$
$c, \frac{3}{5} (x+1) +\frac{1}{10} = \frac{-3}{5} .$
$d, \frac{x-2}{-3} = \frac{-12}{x-2} .$
$e, \frac{x+1}{4} = \frac{x-5}{5} .$
Ai giải nhanh mk tick !
                               (vô danh).​​