Question

e essa conta x-x/7=-3

Answer 1

x-x=-3
   7  m.m.c


7x-1x=-3
  7


7x-1x=7.(-3)
7x-1x=-21
6x=-21
x=-21/6 divididos por 3
x=-7/2

Answer 2

$x-\frac{x}{7} =-3 => \frac{7x-x}{7}=-3 => \frac{6x}{7}=-3 => 6x=-21$
$x=\frac{-21}{6} = x=\frac{-7}{2}$

Um abraço ai :)