Answer:
66.69
Step-by-step explanation:
You start off with -3.9 x -5.7 which gives you a positive, and that positive is 22.23, then you multiply that number by 3, and you get 66.69.
Because the two angles on the right add to 180 degrees, we can create this system:

We can also prove that

, which, when solved, shows that

.
When plugged in to the original equation, we find that y = 105 degrees.
Answer:
d=-4 and a=10
Step-by-step explanation:
The sum of a arithmetic sequence is given by (n/2)*(2a+(n-1)d). Comparing coefficients with the given Sn, we have; a-d/2=12 and d/2=-2, d=-4 and a=10.
Answer:
6.5 seconds
Step-by-step explanation:
Keep in mind that when
, this is the same height for both when the model rocket takes off and lands, so when the rocket lands, time is positive. Thus:

So, the amount of seconds that the model rocket stayed above the ground since it left the platform is 6.5 seconds
Answer:
a = b / 6
Step-by-step explanation: