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!
We know we have $4.40 for 4. Divide 4.40 by 4, you get 1.10. So it's $1.10 per notebook. Therefore, divide 6.60 by 1.10. You get 6, so you can get six notebooks with $6.60.
Hope this helps!
.6666666667 that is a equivalent decimal
Answer:
y= -1
Step-by-step explanation:
A horizontal line would mean that it has no slope, since the line is not decreasing or increasing. The horizontal line drawn through (0, -1) would pass through (-2, -1), since they share the same y coordinate.
