Final answer:
The amount of rain that fell this week, after a 5% decrease from last week's x inches, can be represented by the expressions x - (0.05 * x) or 0.95 * x, both of which calculate to 95% of x.
Step-by-step explanation:
Last week, it rained x inches. This week the amount of rain decreased by 5%. To represent the amount of rain that fell this week, we can calculate 5% of x and then subtract that from x. The expression to represent this calculation would be x - (0.05 * x) or 0.95 * x. Both expressions result in the same value, which is 95% of the original amount of rainfall, x.