Answer:
(4x+1)= 81
Step-by-step explanation:
4x+1= 81
4x= 81 - 1
4x= 80
x= 80/4
x= 20
The half life is 138 days, meaning exactly half of the material will decay after this time. Use this information to find the decay factor
:

Then after 250 days, there will be

grams left.
Answer:
40 miles a day
Step-by-step explanation:
The difference in fixed charge is $20; the difference in mileage charge is $0.50 per mile. So it will take $20/$0.50 = 40 miles for the extra mileage cost to eat up the savings in fixed cost. At that mileage, both companies will charge the same amount:
A: 90 + 0.30·40 = 102
B: 70 + 0.80·40 = 102
2 gallons.
.
.
EXPLANATION: 20.5ft x 16.4ft = 336.2
.
.
336.2 divided by 200= 1.68 gallons.
.
.
We cannot buy 1.68 gallons of paint and so the minimum we can buy is 2 gallons