3. 6/3 equals 2 and 9 divided by 3 equals 3, so a simplified expresssion would say (2n^2)-3.
No solution is your answer
It’s 21 because 252 divided by 12 equals 21
Answer:
By the time she achieves her 26 mile goal Andrea will have run 176 miles.
Step-by-step explanation:
Since Andrea runs 4 miles every day, but she wants to increase her distance in order to run a 26 mile marathon and she decides to add 2 miles each day to her distance until she achieves her goal, to determine, if she starts with 6 miles today, how many miles will she have run in total, by the time she achieves her 26 mile goal the following calculation should be performed:
6 + 8 + 10 + 12 + 14 + 16 + 18 + 20 + 22 + 24 + 26 = X
14 + 22 + 30 + 38 + 46 + 26 = X
36 + 68 + 72 = X
36 + 140 = X
176 = X
So, by the time she achieves her 26 mile goal Andrea will have run 176 miles.
Answer:
512
Step-by-step explanation:
Suppose we ask how many subsets of {1,2,3,4,5} add up to a number ≥8. The crucial idea is that we partition the set into two parts; these two parts are called complements of each other. Obviously, the sum of the two parts must add up to 15. Exactly one of those parts is therefore ≥8. There must be at least one such part, because of the pigeonhole principle (specifically, two 7's are sufficient only to add up to 14). And if one part has sum ≥8, the other part—its complement—must have sum ≤15−8=7
.
For instance, if I divide the set into parts {1,2,4}
and {3,5}, the first part adds up to 7, and its complement adds up to 8
.
Once one makes that observation, the rest of the proof is straightforward. There are 25=32
different subsets of this set (including itself and the empty set). For each one, either its sum, or its complement's sum (but not both), must be ≥8. Since exactly half of the subsets have sum ≥8, the number of such subsets is 32/2, or 16.
