Answer:

Step-by-step explanation:
Given the geometric sequence:
5, −10, 20, −40, ...
The first term is a = 5
And the common ratio = r = -10/5 = -2
The general rule of geometric sequence is

So, the rule for the given geometric sequence is:

Answer:
a₄ = - 15
Step-by-step explanation:
Using the recursive formula and a₁ = 17 , then
a₂ = a₁ - 8 = 17 - 8 = 9
a₃ = a₂ - 8 = 9 - 8 = 1
a₃ = a₂ - 8 = 1 - 8 = - 7
a₄ = a₃ - 8 = - 7 - 8 = - 15
Answer: 
This is the same as 
All we're doing is adding 'a' and
since the term "sum" is the result of adding two or more numbers.
One quarter of a number is the same as dividing by 4.
Example: one quarter of 28 = 
Answer:
2x+3+x2 if x=4 is 27
Step-by-step explanation:
2*x or 2*4=8
8+3=11;
and x or 4 times itself is 16
so we add it all together and get 27.
Have a great day!