There are technically two ways to solve.
Forward:
2(x - 3) = x + 4 Simplify
2x - 6 = x + 4 Get like terms on opposite sides of the equal sign
2x - 6 + 6 - x = x + 4 - x + 6 Positve and negatives cancel out
2x - x = 4 + 6 Simplify
x = 10
Backward:
2(x - 3) = x + 4 Divide both sides by 2
2(x - 3) /2 = (x + 4) /2
(x - 3) = x /2 + 4 / 2 Simplify
x - 3 = 1/2x + 2 Get like terms on opposite sides of the equal sign
x - 3 + 3 - 1/2x = 1/2x + 2 -1/2x + 3 Simplify
x - 1/2x = 2 + 3 Simplify
1/2x = 5 Multiply both sides by 2
2 * 1/2x = 5 * 2 Simplify
x = 10
Both methods will get you to the same answer, but one may be faster and easier than the other, depending on the equation itself.
One method does the Order of Operations forwards, the other goes backwards. One may be preferred over the other, depending on which way you like best or which way is best suited for the equation.