Paula knits hats. The number of hats h she can knit varies directly with the amount of yarn (y) in yards she has. The constant o
1 answer:
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The question is incomplete. Here is the complete question:
A machine covers 5/8 square foot in 1/4 hour. what is the unit rate?
Answer:
2.5 square feet per hour
Step-by-step explanation:
Given:
Area covered by a machine =
Time taken to cover the given area =
Now, unit rate of the first quantity with respect to second quantity is the magnitude of the first quantity being when the second quantity is one unit.
Here, the first quantity is the area covered and the second quantity is the time taken.
So, unit rate is the area covered by the machine in 1 hour.
In order to find that, we use the unitary method and divide the area by the total time taken. Therefore,
Thus, the unit rate is 2.5 square feet per hour.
Question:
Write out the first three terms and the last term. Then use the formula for the sum of the first n terms of an arithmetic sequence to find the indicated sum.
30
∑ (−3i+5)
i=1
Answer:
The first three terms are : 2, -1 and -4
The last term is: -85
The sum of the sequence is: -1245
Step-by-step explanation:
Given;
==================================
30
∑ (−3i+5) -------------------(i)
i=1
==================================
Where the ith term aₙ is given by;
=
-------------------(ii)
(a) Therefore, to get the first three terms (), we substitute i=1,2 and 3 into equation (ii) as follows;
=
= 2
Since the sum expression in equation (i) goes from i=1 to 30, then the last term of the sequence is when i = 30. This is given by;
(b) The sum of an arithmetic sequence is given by;
-----------------(iii)
Where;
n = number of terms in the sequence = 30
= first term = 2
= last term = -85
Substitute the corresponding values of n, and
into equation (iii) as follows;
= 15[-83]
= -1245