That's not valid! x + 2 can be thought of as a single number that is dividing into 1, and if you are multiplying the 2 by 2, you have to multiply the x by 2 as well.
Maybe if you substituted x + 2 and x + 4 as a single variable, you will see how your method was wrong and you will also see the correct way to solve this problem:
Simplify this just like you did the example, and at the end, put in the true values of j and v back in.