Answer:
Explicit: -2*2^(n-1)
Recursive: 2*aₙ₋₁
Step-by-step explanation:
To write a explicit formula for this geometric sequence you follow the following formula/template
Firstnumber*commonratio^(n-1)
Seeing that the common ratio is 2 we can start plugging numbers in and get
-2*2^(n-1)
For a recursive formula we follow the following template
common ratio * the n-1 term
So we could write this as
2*aₙ₋₁
Answer:
x = 5, Y = 4
Step-by-step explanation:
3x -2y = 7
-3x +9y = 21. (multiple the whole thing by 3 to get the xs to cancel)
7y = 28
y = 4
substitute y to find x
3x - 2(4) = 7
3x -8 = 7
3x = 15
x = 5
$80-$35
=$45
$45+$115
=$160
his account balance is $160