If `y_1` and `y_2` are the solution of the differential equation `(dy)/(dx)+P y=Q` , where `P` and `Q` are functions of `x` alone and `y_2=y_1z` , then prove that `z=1+cdote^(-fQ/(y_1)dx),` where `c` is an arbitrary constant.

Explanation

To solve the problem, we start with the given differential equation and the relationships between the solutions \( y_1 \) and \( y_2 \).

### Step 1: Write down the differential equations
We have two solutions \( y_1 \) and \( y_2 \) of the differential equation:
\[ \frac{dy}{dx} + P y = Q \]
Thus, we can write:
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