The answer to this question is 380 minutes
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:
x=−y−1
Step-by-step explanation:
y=−x−1
Step 1: Flip the equation.
−x−1=y
Step 2: Add 1 to both sides.
−x−1+1=y+1
−x=y+1
Step 3: Divide both sides by -1.
−x
−1
=
y+1
−1
x=−y−1
Answer:
x-less than-or-equal-to 3
Step-by-step explanation:
4x + 6 < 18 (less than or equal to)
4x < 12 (less than or equal to) x < 3 (less than or equal to)
