It is systematic because they are going every tenth person, in a random manner.
Real answer
48
*26
------
1,248
Estimate
50
*25
------
1,250
So the answer is..
Estimating is helpful because it makes sure you answered correctly. No, this answer is incorrect and if he had done the estimate he could have seen how he was wrong.
To find that one, just look at the highest exponent. In the given equation that would be 4, so there can be at most 4 zeros in this function.
Step-by-step explanation:
Find two numbers that multiply to give ac (in other words a times c), and add to give b.
Rewrite the middle with those numbers:
Step 3: Factor the first two and last two terms separately: