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
Answer:
D
Step-by-step explanation:
Put m+2 in place of 'x'
(m+2)^2 + 1 <======expand
m^2 + 4m + 4 + 1 =
m^2 + 4m + 5
Answer:
20
Step-by-step explanation:
i think but not fur shure
Answer:
x=13
Step-by-step explanation:
because they're alternate adjacent angles:
5x=78-x
6x=78
x=13
