There are five steps to solving simple algebraic equations
For our equation since we don't have fractions or parenthesis, we can begin with step 3 and using a rule of algebra of performing the inverse of a function to move it from one side of the equation to the other. In order to move +6x to the left side of the equation, we will subtract 6x from both sides. Likewise, to move the -4x to the left side, we will add 4x to both sides. The same rule applies to the known variables.
8x + 7 - 3x = 6x + 19 - 4x now becomes
8x - 3x - 6x + 4x = 19 - 7
Next, reduce the complexity of the equation by combining like terms on each side of the equation
3x = 12
Lastly, remove the coefficient from the unknown term, again using the rule of performing the inverse of a function. The inverse of 3 is 1/3, so multiply both sides of the equation by 1/3. Or to state it another way, divide both sides by 3.
x = 4.
First combine terms with x's in them and combine the others to get:
5x + 7 = 2x + 19
Then subtract 2x from both sides and subtract 7 from both sides to get:
3x = 12