Let the event 
The the probability of the events


The conditional probability

Answer:
3x(x – 3)(x2 + 3x + 9)
Step-by-step explanation:
Because 3x4 – 81x=3x4-3x3
and the formula is
a3-b3=(a-b)(a2+ab+b2)
but since here it is 3x4 we put 3x before the formula.
Answer:
550
Step-by-step explanation:
To round 553 to the tens place, we would need to identify the value of the digit in the ones place.
If the digit in the ones place is greater than 5, we increase the tens place by 1 & convert the ones place into a 0.
If not, we leave the tens place as is & convert the ones place into a 0.
Since 3 is less than 5, we round 553 to 550 so you are correct.