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:
30y+14
Step-by-step explanation:
add the values of all the sides together: (5y+4) + (5y+4) + (10y+3) + (10y+3) = (5y + 5y + 10y + 10y) + (4 + 4 + 3 + 3)= 30y + 14
Answer:
0.4 or 4/10 as a fraction
Step-by-step explanation:
