Expression:
To obtain the expression, we need to follow three steps in order:

1. Multiply Z by 5
2. Divide the product obtained by 7
3. Subtract the result from 3

Step 1: Multiply Z by 5
To begin, we multiply the value of Z by 5. This means that we take the value of Z and multiply it by 5.

Step 2: Divide the product obtained by 7
After obtaining the product from step 1, we divide it by 7. This means that we take the product obtained in step 1 and divide it by 7.

Step 3: Subtract the result from 3
Finally, we subtract the result obtained in step 2 from 3. This means that we take the result obtained in step 2 and subtract it from 3.

Explanation:
Let's assume the value of Z is 10. We will now calculate the expression step by step.

1. Multiply Z by 5:
Z * 5 = 10 * 5 = 50

2. Divide the product obtained by 7:
50 / 7 ≈ 7.142857143 (rounded to 9 decimal places)

3. Subtract the result from 3:
3 - 7.142857143 ≈ -4.142857143 (rounded to 9 decimal places)

Therefore, if we start with the value of Z as 10 and follow the given expression, the final result will be approximately -4.142857143.

It is important to note that the actual result may vary depending on the value of Z. The expression provided is a general representation of the steps to be followed, and the specific value of Z will determine the final result.