Answer:the percentage decrease is 36.67%
Step-by-step explanation:
Initial amount of sugar in his diet is 15 spoons in a day. Currently, the amount of sugar in his diet is 9 1/2 spoons in a day. Converting to decimal, it becomes 9.5 spoon in a day. The amount by which he reduced his sugar intake is 15 - 9.5 = 5.5 spoons.
Percentage decrease would be expressed as
Amount by which the intake decreased/ initial intake × 100
It becomes
5.5/15 × 100 = 36.67%
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Find area of one triangle
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Area of triangle = 1/2 x base x height
Area of triangle = 1/2 x 9 x 11.75
Area of triangle = 52.875 ft²
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Find area of two triangles
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Area of 2 triangles = 52.875 x 2
Area of 2 triangles = 105.75 ft²
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Find the cost of the flower beds
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1 ft² = $4.25
105.75 ft² = 105.75 x 4.25
105.75 ft² = $449.44 (nearest hundredth)
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Answer: $449.44
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Part A
Answer: The common ratio is -2
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Explanation:
To get the common ratio r, we divide any term by the previous one
One example:
r = common ratio
r = (second term)/(first term)
r = (-2)/(1)
r = -2
Another example:
r = common ratio
r = (third term)/(second term)
r = (4)/(-2)
r = -2
and we get the same common ratio every time
Side Note: each term is multiplied by -2 to get the next term
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Part B
Answer:
The rule for the sequence is
a(n) = (-2)^(n-1)
where n starts at n = 1
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Explanation:
Recall that any geometric sequence has the nth term
a(n) = a*(r)^(n-1)
where the 'a' on the right side is the first term and r is the common ratio
The first term given to use is a = 1 and the common ratio found in part A above was r = -2
So,
a(n) = a*(r)^(n-1)
a(n) = 1*(-2)^(n-1)
a(n) = (-2)^(n-1)
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Part C
Answer: The next three terms are 16, -32, 64
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Explanation:
We can simply multiply each previous term by -2 to get the next term. Do this three times to generate the next three terms
-8*(-2) = 16
16*(-2) = -32
-32*(-2) = 64
showing that the next three terms are 16, -32, and 64
An alternative is to use the formula found in part B
Plug in n = 5 to find the fifth term
a(n) = (-2)^(n-1)
a(5) = (-2)^(5-1)
a(5) = (-2)^(4)
a(5) = 16 .... which matches with what we got earlier
Then plug in n = 6
a(n) = (-2)^(n-1)
a(6) = (-2)^(6-1)
a(6) = (-2)^(5)
a(6) = -32 .... which matches with what we got earlier
Then plug in n = 7
a(n) = (-2)^(n-1)
a(7) = (-2)^(7-1)
a(7) = (-2)^(6)
a(7) = 64 .... which matches with what we got earlier
while the second method takes a bit more work, its handy for when you want to find terms beyond the given sequence (eg: the 28th term)
Answer:
Step-by-step explanation:
