Sum of an infinite geometric sequence with the common ratio r, and the first term a1 is

we notice
-2 times -1/4=1/2,
1/2 times -1/4=-1/8
so a1=-2
r=-1/4 or -0.25
so the sum is

=

=

=

=
the sum is -8/5 or -1.6
Answer:
x = 2
Step-by-step explanation:
First isolate the variable:
10x - 4 = 16
+4 +4
10x = 20
Then get x by itself:
10x = 20
x = 20/10
x = 10
Answer:
y = 30
Step-by-step explanation:
We can use ratio's to solve this
40 20
----- = -----------
100 20 + y
Using cross products
40 * (20+y) = 20*100
Distribute
800 + 40y = 2000
Subtract 800 from each side
40y = 2000-800
40y = 1200
Divide by 40
y = 1200/40
y =30
Answer:
Supplementary
Step-by-step explanation:
Supplementary angles add to 180 degrees.