Question

How can we solve linear equations?

Answer 1

The basic and the most important rule to solve an equation is no matter what kind of equation one is dealing with - linear or otherwise - whatever one does to the one side, it must be done in the same manner on the other side.
Whatever one does to an equation, repeat the same thing to both the sides of that equation.
Eg: Solve x - 3 = -5
Since we want to get x by itself, we don't want the "-3" that's the variable. The opposite of subtraction is addition, so we'll undo the -3 by adding 3 to both sides, and then adding down:
$x-3=-5+3+3\underset{–}{}x=-2$
Then the solution is x = -2.