Answer: Choice A
S9 = (9/2)*(2+26)
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The formula is
Sn = (n/2)*(a1+an)
where
Sn = sum of the first n terms (nth partial sum)
n = number of terms
a1 = first term
an = nth term
In this case,
n = 9
a1 = 2 (plug in n = 1 into the formula an = 3n-1 and simplify)
an = a9 = 26 (plug n = 9 into the formula an = 3n-1 and simplify)
So,
Sn = (n/2)*(a1+an)
S9 = (9/2)*(2+26)
will help us find the sum of the first 9 terms of this arithmetic sequence
Answer:
215 cm³
8.6 cm
Step-by-step explanation:
given,
density = 10.2 g/cm³
mass = 2.193 kg = 2193g
a. Volume = mass / density
=2193 / 10.2
= 215 cm³
b. given that base area = 25cm²
volume = base area x thickness
thickness = volume / base area
= 215 / 25
= 8.6 cm
Answer:
EF = 1.5. DF = 2.
Step-by-step explanation:
DE is half of AB so EF is half of BC and DF is half of AC.
Answer:gnhbk j bmnj
Step-by-step explanation:
