An = a1 * r^(n-1)
-405 = -5*3^(n-1)
3^(n-1) = 81
3^4 = 81 so n-1 = 3 and n = 4
Sn = S4 = -5 (1 - 3^4) / ( 1 - 3) = 400 / -2 = -200 Answer
Start by getting all terms with x on one side and all terms without on the other.
6x+7=8x-15
subtract 6x from both sides
7=2x-15
add 15 to both sides
22=2x
divide both sides by 2
11=x
Surface area o fthe ball = 4 * 3.14 * radius^2
if diameter = 1.680 then radius = 1/2 * 1.680 = 0.84
so surface area = 4 * 3.14 * 0.84^2 = 8.862
Answer:
a = -4/9
Step-by-step explanation:
(9a + 4) = 0
Subtract 4 from each side
9a + 4-4 = 0-4
9a = -4
Divide each side by 9
9a/9 = -4/9
a = -4/9
Subtract. it from when you do good school