Answer:
a(4) = 15/4
Step-by-step explanation:
The general formula for a geometric series with common ratio r and first term a(1) is
a(n) = a(1)*r^(n - 1)
and so, if a(1) = 30 and r = 1/2, we have
a(n) = 30*(1/2)^(n - 1)
and the fourth term is then:
a(4) = 30*(1/2)^(4 - 1) = 30/8 = 15/4
9514 1404 393
Answer:
D. (4, -6)
Step-by-step explanation:
Since the heights of both triangles are the same (CD), their areas are proportional to their bases. That is ...
AC : CB = 3 : 4
In terms of coordinates, ...
4(C -A) = 3(B -C) . . . . multiply the ratios by 4(CB)
4C -4A = 3B -3C . . . .simplify
7C = 4A +3B . . . . . . . isolate C
C = (4A +3B)/7 . . . . . divide by 7
C = (4(1, -9) +3(8, -2))/7 = (28, -42)/7 . . . . substitute given coordinates
C = (4, -6)
2/3 = 8/12
1/4 = 3/12
hence fraction of girls with neither blue or black eyes = 1 - 8/12 -3/12 = 1/12
so
so
take differential calculus
you will find x then y
