Evaluating the given sequence, it is evident that the next number is twice the number prior to it. Thus, the given is a geometric sequence with first term (a1) equal to 1 and common ratio of 2. The geometric series may be calculated by the equation,
Sn = a1 x (1 - r^n) / (1 - r)
where Sn is the sum of n terms in this case, n = 11.
Substituting the known values,
<span> Sn = 1 x (1 - 2^11) / (1 - 2) = 2047
</span>
Thus, S11 is 2047.
Let s=number of seeds and t=number of days...
st=120 and (s+10)(t-2)=120
From the first we can say t=120/s, now using this value of t in the second equation gives us:
(s+10)(120/s-2)=120
(s+10)(120-2s)/s=120
(s+10)(120-2s)=120s
120s-2s^2+1200-20s=120s
2s^2+20s-1200=0
s^2+10s-600=0
(s+30)(s-20)=0, since s>0
s=20, and since she planted s+10 seeds per day to finish two days earlier:
20+10=30
She planted 30 seeds per day.
First, we must solve for the radius of the sphere:
V=
r=(3
)
r=(3*
)
r≈5.99
Second, we must solve for surface area:
A=4
A=4*
*
A≈450.88
Answer:
-4m-3
Step-by-step explanation:
-0.25 times 16 is the same thing as dividing 16 by -4. 16m divided by -4 is -4m
-0.25 times 12 is the same thing as dividing 12 by -4. 12 divided by -4 is -3
