9514 1404 393
Answer:
geometric sequence
Step-by-step explanation:
The terms of the sequence have a common ratio of -12/3 = -4, so the sequence is geometric. The general term is ...
an = 3(-4)^(n-1)
so the sum can be written as ...
(Note the summation starts at n=0, corresponding to a first term of 3.)
Answer:
Step-by-step explanation:
From the attachment, we can see that
<EBF = 33°
<EBD = 33°
<FED = 114°
<FBD = 66°
Part 2
The value of y is either of 70 or -80. But then, we all know that speed can not be negative, so the speed was 70 km/h
The return speed is y + 10 = 70 + 10 = 80 km/h
Total time = 350/70 + 350/(70+10)
Total time = 5 + 4.375
Total time = 9.375 hr
