Answer:
3x=24y
-12x+9y=7
let me know if this helps :3
Step-by-step explanation:
<span>The reference angle is closest to the x-axis.
I will assume the above is 7pi/6. That would be a reference angle of pi/6, and the sin in the 3rd quadrant is negative, so the sin theta = - 0.5</span>
Let the profit at the first year be X
3x=114000
Solve for x by dividing each side by 3
3x/3=114000/3
X=38,000
So the profit was 38000
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!