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:
x=2.5 cups are needed for 2 pies
Step-by-step explanation:
4/5 or 0.8
Fraction form: 4/5x = 2 x= 5/4
Decimial form: 0.8x = 2 x = 2.5
Mixed number form: 2 1/2
Hope that helped :)
Answer:
The artist used 
more of silver wire
Step-by-step explanation:
see the attached figure to better understand the problem
step 1
we know that
The Perimeter of the square is equal to
where
a is the length side of the square
so
so
Each side of the square has a length of 10 in
step 2
Find the circumference of the circle
The diameter of the circle is equal to the length of the side of the square
The circumference is equal to
we have
substitute
step 3
Find the difference
Answer:
Option A is correct, i.e. x = -3, x = 7.
Step-by-step explanation:
Given the equation is x² -4x -21 = 0.
We can compare it with general quadratic equation i.e. ax² +bx +c =0.
then a = 1, b = -4, c = -21.
We can use Quadratic formula as follows:-
x = ( -b ± √(b²-4ac) )/2a
x = ( +4 ± √(16-4*1*-21) )/2*1
x = ( +4 ± √(16+84) )/2
x = ( +4 ± √(100) )/2
x = ( +4 ± 10 )/2
x = (4+10)/2 or x = (4-10)/2
x = 14/2 or x = -6/2
x = 7 or x = -3
Hence, option A is correct, i.e. x = -3, x = 7.
(2,7) is going to be the answer for that
