Final answer:
The expression 'Twice a number decreased by 8' can be translated as '2x - 8'.
Step-by-step explanation:
The expression 'Twice a number decreased by 8' can be translated as '2x - 8'.
To understand why, let's break it down. The phrase 'Twice a number' means 2 times the number, which can be written as 2x. The phrase 'decreased by 8' means subtracting 8 from the previous result, which gives us 2x - 8.
Therefore, the correct translation of the expression is 2x - 8.