Answer:
D=5/2. 5 over 2
Step-by-step explanation:
Cross multiply and solve for D
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!
140 / 100 * X = 56
X = 56 * 100 / 140 = 5600 / 140 = 40
7n-84 would be your correct answer, 7 times n is 7n. 12 times 7 is 84 so therefore your answer would be 7n-84
