Answer:
He needs 0.48 liters of plant food.
Yes, one bottle is enough for 12 weeks.
Step-by-step explanation:
William uses 40 mililiters each week.
Let be [tex]x[/tex] the total amount of liquid plant food he needs for 12 weeks. It can be calculated by multiplying 12 by 0.40 mililiters. Then:
[tex]x=(12)(40mL)\\x=480mL[/tex]
Make the conversion from mililters to liters (Remember that 1 liter has 1,000 mililiters):
[tex](480mL)(\frac{1L}{1,000mL})=0.48L[/tex]
Then, he needs for 12 weeks:
[tex]x=0.48L[/tex]
As he bought a 0.5 -liter bottle of liquid plant food and he needs 0.48 liters for 12 weeks, you can conclude that one bottle is enough for 12 weeks.