Answer:
B.) 18
Step-by-step explanation:
To find the correct b value we use this formula
b² - 4ac = 0
b = What we are solving for
a = 1
c = 81
b² - 4(1)(81) = 0
b² - 324 = 0
b² = 324

b = ±18
And 18 is one of the answer choices
So B.) 18 is the correct answer.
Answer:
7,10,13
Step-by-step explanation:
60 minutes is 20% of 300 minutes
Answer:
2.83
Step-by-step explanation:
25 round off is equal to 30
so we can write 2.825 = 2.83 in form of 2 digits
83 round off to 80
2.83 is equal to 2.8