First term: a1 = 151
common difference: d = -14 (we decrease by 14 each time, eg, 151-14 = 137)
nth term of this arithmetic sequence is...
an = a1+d(n-1)
an = 151+(-14)(n-1)
an = 151-14n+14
an = -14n+165
This will be used in the formula below
Sn = n*(a1+an)/2
<span>Sn = n*(151+(-14n+165))/2
</span><span>S26 = 26*(151+(-14*26+165))/2 ... replace every n with 26
</span>S26 = -624
The final answer here is choice C) -624
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80p=pr^2+p(2r)^2
80p=pr^2+4pr^2
80=r^2+4r^2
80=5r^2
16=r^2
r=4 for the smaller circle´s radius, and 8 is the larger circle´s radius.
Have a nice day, I hope this was helpful :D
Answer:
Ok
Step-by-step explanation:
I will help you or maybe
I’m sorry but I’m also struggling
Step-by-step explanation:
you look for the slant height and the volume