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.
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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
Grape- 8/20 = 2/5 = 40%
cherry - 7/20 = 35%
lemon - 5/20 = 25%
THey tried to push but the wall doesn't move. So Nobody did any work. Everybody's work done is 0.
Answer:
2 gallons of pure alcohol
Step-by-step explanation:
Let x represent the number of gallons of pure alcohol needed, and create an equation:
4(0.25) + x(1) = (x + 4)0.5
1 + x = 0.5x + 2
x = 0.5x + 1
0.5x = 1
x = 2
So, 2 gallons of pure alcohol should be added.
A perpendicular bisector forms two right angles and splits the line in two equal parts.
The altitude does create two right angles, but doesn't have to create two equal parts.
