I don't think you can convert anything out of a decimal because 0.232 is already a decimal!
What the that needs to be solved
We are given:

Our goal in solving for any variable, in this case is x, we need to isolate x on one side of the variable. Let's start by subtracting 7x from both sides, which will cancel the +7x on the right side. We are then left with:

Now, we want to move that +10 to the other side so our x is all by itself. Let's subtract 10 from both sides, which will cancel the +10 on the right leaving us with:

Since we cannot have a coefficient when solving for x, we need to divide both sides by -3.

When we divide, our answer is:

Answer: 19.5
Step-by-step explanation:
Use Pythagorean theorem to find the diagonal as it is a right triangle.