Answer:
25 minutes 42 seconds 
 
Step-by-step explanation: 
 
The tub will fill at the rate of ... 
 
 2.25 gal/min - 0.50 gal/min = 1.75 gal/min 
 
It will take ... 
 
 45 gal/(1.75 gal/min) ≈ 25.714 min 
 
for the tub to fill. 
 
You can shower for about 25 minutes 42 seconds.
Explanation: