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
Step-by-step explanation:
1. You already got the first step, where D is the midpoint of AC and AB is congruent to BC, since it's given.
2. AD will be congruent to DC, via the definition of a midpoint (a midpoint is the middle point of a line segment, and it splits the segment into two congruent parts)
3. BD is equal to BD, via reflexive property. ( It's a shared side between the two triangles)
4. that means that ΔADB ≅ΔCDB via SSS rule.
5. ∠ABD ≅∠CDB by CPCTC (corresponding parts of congruent triangles are congruent)
Hope this helps! :)
G because she need to sell 20 vases because the cost is 450 and if you divide it by 23 for the price the vases will be sold for it comes to 19.57 and you can't sell .57 of a vase you have to round up to make more than the money spent
Obtuse angle. If wrong I’m sorry lol
Answer:
A
Step-by-step explanation:
