Answer:2
Step-by-step explanation:
X=Marks sister's age
x+11= Marks age
x+11 +8 = 2x+8
x+19=2x +8
x+19-x=2x-x +8
19-8=x+8-8
11=x Marks sisters age in 8 years
11-8= 3 Marks sisters age now
x+11=22 Marks age in 8 years
22-8= 14 Marks age now
Answer:
<h2>-3400</h2>
Step-by-step explanation:
In general, a geometric sequence is given by:
<h3>
a,
ar,
ar^2,
⋯,
ar^n−1 </h3>
In the sequence 20, - 40 , 80,…
First term, a1 = 20
Common ratio, r = - 40 ÷ 20 = - 2
The nth term is = 9th
Sum of finite geometric series : Sn= ( a1 - a1r^n ) / ( 1 - r)
S9 = ( 20 - 20 x (- 2)^9 ) / ( 1 - ( - 2) )
S9 = ( 20 - 20 x - 512 ) / ( 1 + 2 )
S9 = ( 20 - 10240<em> </em>) / ( 3 )
S9 = ( - 10220 ) / 3
<h3>S9 = - 3400 <u>Answer</u> </h3><h2>Hope it's help you.... ^_^❤️</h2>
Answer:
Step-by-step explanation:
This can be represented as exponential decreasing function.
y = a(1 - r)t
a = starting amount
r = rate
t = years
y = 1600(1 - .0725)15
= 1600(.9275)15
= 1600(.32337673)
= 517.40
In 15 years, the forest will shrink in size to 517.40 km2