Answer
6
Work Step by Step
For cross multiplication, we know:
$$\frac{a}{d} =\frac{b}{c} \rightarrow ac=bd$$
Thus, we find:
$$3\left(x+2\right)=x\cdot \:4\\ 3\left(x+2\right)=x\cdot \:4\\ x=6$$
Checking our solution by plugging the given value back into the equation, we assure that the solutions are not extraneous.