There would be 12 people at the party!
In general, with n+1 people, the number of handshakes is the sum of the first n consecutive numbers: 1+2+3+ ... + n.
Since this sum is n(n+1)/2, we need to solve the equation n(n+1)/2 = 66.
This is the quadratic equation n2+ n -132 = 0. Solving for n, we obtain 11 as the answer and deduce that there were 12 people at the party.
Since 66 is a relatively small number, you can also solve this problem with a hand calculator. Add 1 + 2 = + 3 = +... etc. until the total is 66. The last number that you entered (11) is n.
Hope this helps!
Answer:
DATA SET : A
Step-by-step explanation:
Well I answered it on Apex
Answer:

Step-by-step explanation:
Lines form 180 degrees on either side. The negative sign simply implies direction (clockwise instead of counter-clockwise), which is negligible as 180 is exactly half of 360 so you'd form the same line.
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Answer:</h2><h2>c = -24</h2><h2 /><h2>Hope this helps!!</h2>