Answer:
B
Step-by-step explanation:
the dog was coming near.
Answer:
<u>-5 ± √5² - 4 · 1 · 4</u>
2 · 1
Step-by-step explanation:
ax²+bx+c=0 (quadratic equation)
x=<u> -b ± √b² - 4ac</u>
2a
a= 1
b= 5
c= 4
-<u>5 ± √5² - 4 · 1 · 4</u>
2 · 1
Answer: D
Step-by-step explanation:
Answer: -√13/3
Step-by-step explanation:
I answered wrong on my test this was the answer
Answer:
<em>19800 seconds, or 330 minutes, or 5 hours + 30 minutes</em>
Step-by-step explanation:
<u>Number Permutations</u>
We know the phone number has 7 digits, 4 of which are known by Mark. This leaves him 3 digits to guess with. We also know the last one is not zero. The number can be represented as
XXY
Where X can be any digit from 0 to 9 and Y can be any digit from 1 to 9. The first two can be combined in 10x10 ways, and the last one can be of 9 ways, this gives us 10x10x9 = 900 possible permutations.
If each possible number takes him 22 seconds, every possibility will need
22x900=19800 seconds, or 330 minutes, or 5 hours + 30 minutes