Use the formula to evaluate the series -3 + 6 - 12 +24 - ...-az.
1 answer:
Answer:
Your sum = - 1
S = ( (-2)^n - 1), If you let n = z, then S = (-2)^z - 1
Step-by-step explanation:
I can use a formula to find the sum of the first n terms.
we have -3, 6, -12, 24, ... etc.
common ratio = r = -2
first term = -3
a_1 = -3
Then: a_n = a_1 * r ^(n -1)
a_n = (-3) * (-2)^(n - 1) is the general formula for the nth term
Sum of first n terms = S = a_1 * (r^n - 1) / (r - 1)
so...
S = (-3) * ((-2)^n - 1 )/ (-2 - 1)
which simplifies to
S = (-3) *((-2)^n - 1) / (-3)
S = ( (-2)^n - 1)
If you let n = z, then S = (-2)^z - 1
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Answer:
The length and width of the parking lot is 78 meters and 114 meters respectively.
Step-by-step explanation:
Given;
Perimeter of the parking lot =
Solution,
Let the width of the parking lot be x.
Then, according to question length = (x-36).
The perimeter of a rectangle is sum of all the sides of rectangle. Which is given by an expression;
Now substituting the values, we get;
Width =
Length =
Hence the length and width of the parking lot is 78 meters and 114 meters respectively.