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!
The numbers that are irrational are B. √72 and D.√23.
<h3>What are irrational numbers?</h3>
Irrational numbers are those that have infinite numbers after the decimal. These numbers are also none repeating.
When the above are solved:
√25 = 5
√144 = 12
√23 = 4.79583152331...
√72 = 8.48528137424...
The only two numbers with non-repeating and infinite numbers are √72 and √23.
Find out more on irrational numbers at brainly.com/question/20400557
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So 36% of x is 18
percent is parts out of 100
36%=36/100=0.36
'of' can be translated as muitiply
0.36 times x=18
divide both sdies by .36
x=50
the number is 50
x= 2
Step-by-step explanation:
The answer for what does x= is,
x = 2
I hope this helps you
6y=13-2x
y=13-2x/6
y=13/6-1/3x
