Hello :
<span>the nth term of a geometric sequence is :
Un = Up ×r^(n-p) . r is the common ratio
for : p=5 and n= 2
U5 = U2 ×r^3
16 = -2 r^3
r^3 = -8
but : -8 = (-2)^3
so : r = -2
Un = U2 × r^(n-2)
Un = -2 ×(-2)^(n-2)= (-2)^(n-2+1)
</span><span>the nth term of a geometric sequenceis : Un = (-2)^(n-1)</span>
Sn=sum of the n terms of the geometric sequence.
a= the first term
r=the common ratio
n=numbers of terms.
Sn=a[(1-r^n)/(1-r)]
In this case:
a=-3
r=a₂/a₁=15/-3=-5
n=9
S₉=-3[(1-(-5)⁹) / (1-(-5))=
S₉=-3(1+1953125)/6)=
S₉=-3(1953126/6)=
S₉=-3(325521)
S₉=-976563
<span>Answer: A. -976563
hope this helps :^)</span>
Answer:
C.) 35
Step-by-step explanation:
Supplementary angles equal 180, therefore, the opposite side of both the angles 90 and 125, must be 180 minus that value.
180-125=55
180-90=90
Now we know that the two inside angles equal 55 and 90. Together, that's 145.
Since all the angles within a triangle equal 180, we subtract the two other angles to find p.
180-145=35