Answer:
40
Step-by-step explanation:
y = 50 + .4 x 40
y = 30 + .9 x 40
y = 66 for both equations
A=84 and r=1/5
Since r, the common ratio squared is less than one, the sum will converge to a limit. Rule: if r^2<1 infinite series converges, otherwise it diverges.
Since the sum of any geometric sequence is:
s(n)=a(1-r^n)/(1-r)
And if r^2<1, (1-r^n) becomes 1-0=1 as n approaches infinity.
So whenever r^2<1 the sum of the infinite series is just:
s(n)=a/(1-r)
Since a=84 and r=1/5 this infinite series has a sum of:
s(n)=84/(1-1/5)
s(n)=84/(4/5)
s(n)=5(84)/4
s(n)=105
Answer:
27
Step-by-step explanation:
y=kx
9=k*5, so k=9/5
when x=15
y=(9/5)*15=27
