Question

In a geometric sequence, a7=14 and r= -1/2. What is the 10th term of the sequence?

• -3.50
• -1.75
• 1.75
• 3.50

Answer 1

1) a yes 2

2) c 405

3) b an=-4 (-2) -64

4) a triangle 4

5) b -1.75

Answer 2

we know that
in geometric sequence the formula is
an=a1*r^(n-1)
where
an---------> is the nth term
a1 --------> is the first term
n ----------> is the number of the term
r ----------> is the common ratio
a7=14
r=(-1/2)

Step 1
find the a1 term
a7=a1*r^(7-1)-------------> 14=a1*(-1/2)^(6)
a1=14/[(-1/2)^(6)]------------> a1=896

Step 2
find the a10 term
a10=a1*r^(10-1)--------> 896*(-1/2)^9=-1.75

the answer is a10=-1.75