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:
y - 3y^2 + 4y^2 - 12y
y^2 - 11y
Step-by-step explanation:
Answer:
First do the Base multiplied by the Height.
After divide by 2
Step-by-step explanation:
Answer:
y = 4x - 1
Step-by-step explanation:
Answer:
8 hours worked, 64 dollars
56 dollars, 7 hours worked
themepark:
5 hours worked, 45 dollars
6 hours worked, 54 dollars
8 hours worked, 72 dollars
working at the themepark earns 5 extra dollars when they work for 5 hours.
