The correct answer for this very hard equation would happen to be 12 because 18+12 happens to equal 30 and 42-30 just so happens to equal 12
The answer is D due to it
Ratio of classes A, B, C = 4 : 6 : 5, respectively
4 + 6 + 5 = 15
So, class A represents 4/15 of the TOTAL population
Class B represents 6/15 of the TOTAL population
Class C represents 5/15 of the TOTAL population
So, weighted average of 3 groups combined = (4/15)(65) + (6/15)(80) + (5/15)(77)
= 260/15 + 480/15 + 385/15
= 1125/15
= 75
Answer: B
K - 2k = 15 + 1 + 6k - 2
-k = (15 + 1 - 2) + 6k
-k = 14 + 6k |subtract 6k from both sides
-7k = 14 |divide both sides by (-7)
k = -2
Y^2 + 18y + 81 = 0
(y + 9)^2 = 0
y + 9 = 0
y = -9
