Number one is c
number two is a
number three is d
Each number in the sum is even, so we can remove a factor of 2.
2 + 4 + 6 + 8 + ... + 78 + 80 = 2 (1 + 2 + 3 + 4 + ... + 39 + 40)
Use whatever technique you used in (a) and (b) to compute the sum
1 + 2 + 3 + 4 + ... + 39 + 40
With Gauss's method, for instance, we have
S = 1 + 2 + 3 + ... + 38 + 39 + 40
S = 40 + 39 + 38 + ... + 3 + 2 + 1
2S = (1 + 40) + (2 + 39) + ... + (39 + 2) + (40 + 1) = 40×41
S = 20×21 = 420
Then the sum you want is 2×420 = 840.
Answer:
.
Step-by-step explanation:
Answer:
27.9 dollars
Step-by-step explanation:
2.70= 15 percent
2.70x2=5.4=30 percent
5.4+2.70=8.1=45 percent
8.1x2=16.2=95 percent
95 percent + 15 percent=18.9
18.9=105 percent
in order to subtract 5 percent we need to find 5 percent by dividing 2.70 by 3
which = .9
18.9+9=27.9
100 percent is 27.9 dollars
I think it should be angle bisector
