Answer:
B :step 2 she didnt collect all the like terms and calculate
Step-by-step explanation:
first rewrite remove all ( )Parentheses
2nd collect all like terms and calculate
a^4 + 7a -16 -12^a^3 + 5a -3
a^4 + 12a - 19 - 12a^3 ( Like terms are 7a +5a and -16 +-3)
so she skipped the second step
The 99.87th percentile, or the area to the left of the 3 standard deviation mark it 99.87% better than everyone/everything else.
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
The first one is C and the second one is B
