Explain the solving of the equation 3x+15=0?

In order to solve the linear equation, we'll have to find
a value for x so that the equation to hold, even after the substitution of the unknown x
with the found value was made.

A proper manner to solve
this type of equation would be to subtract, both sides of the equation, the opposite
value of the one of the left side, so that, in the end, the left side to contain only
the unknown x.

3x+15-15 =
0-15

3x=-15

Now, to move 3
across the equal sign, we need to divide both sides of the equation with
3.

3x/3 =
-15/3

x =
-5