X= -41/2
12x-20=14x+21
12x-20+20=14x+21+20
12x=14x+41
12x-14x=14x+41-14x
-2x=41
-2x/-2=41/-2
x=-41/2
Let x be the value of the third term.
Since it's a geometric sequence, then:
Third term/Second term = Fourth term/Third term
x/20 = 11.25/x
Cross multiplication:
x^2 = 225
x = 15
So since the ratio is constant, then it is
x/20 = 15/20 = 3/4
So the common ratio is 3/4 or 0.75.
The equation for profit is expected to be
daily profit = (profit on plate)*(number of plates) +(profit on cup)*(number of cups)
We are told that
profit on plate = k
profit on cup = k-1
Matching these to the expression above, we find
x = number of plates
y = number of cups
You are asked what y represents. It is
A. The number of cups sold in one day.
F(n+1)=-1/2f(n)
f(n)=-2f(n+1)
given f(1)=120
-2f(1+1)=120
f(2)=-60
f(2)=-2f(2+1)=-60
f(3)=30
f(3)=-2f(3+1)=30
f(4)=-15
f(4)=-2f(4+1)=-15
f(5)=15/2