4a + 7b = 38 -> (1)
9a + 7b = 68 -> (2)
Subtract (1) from (2),
9a - 4a + 7b - 7b = 68 - 38
5a = 30
a = 6
This is the answer .
If you need more explanation I am free
Answer: 6.75 or 6 3/4
Step-by-step explanation: 3 3/8 x 2 = 6.75 Brainliest please?
283.5
So you multiply 6.75 by 21 stools to find the total number of meters. Then you multiply that by 2.
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
