Answer:
5:00 pm
Step-by-step explanation:
Let
x -----> the umber of hours
y ----> the total distance in miles
we know that
The distance is equal to the speed multiplied by the time
Find out the distance traveled by Ariel at 11:00 am
11:00 am-09:00 am=2 hours
45(2)=90 miles
so
<em>Ariel's linear equation is</em>
----> equation A
<em>Ariel's brother linear equation is</em>
----> equation B
Equate equation A and equation B
Solve for x
Adds 11:00 am + 6 hours=17:00 =5:00 pm
Answer:
-675
Step-by-step explanation:
The sum can be broken into parts that you know. Here, one of those parts is the sum of numbers 1 to n. That sum is given by n(n+1)/2.
__
Another way to do this is to realize the sequence of numbers is an arithmetic sequence with a first term of 65 and a last term of 67-2·75 = -83.
The sum of an arithmetic sequence is found by multiplying the number of terms by their average value. Their average value is the average of the first and last terms.
The average value of those 75 terms is (65 +(-83))/2 = -9, so their sum is ...
75(-9) = -675
