How do you draw and lable a perimeter using rectangles. The length is x feet the width is( x-7) and write 3 different expression
1 answer:
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Answer:
Step-by-step explanation:
The initial number of mosquitoes is 400000, and they double each day. This represents an exponential growth equation. If t represent days and P represent the population of the mosquitoes, hence this can be represented by the equation:
Also, the predators eat the mosquitoes at a rate of 40,000 mosquitoes/day. This means that each day, the mosquitoes reduce by 40000t, therefore this can be represented by:
Notice that
13 - 9 = 4
17 - 13 = 4
so it's likely that each pair of consecutive terms in the sum differ by 4. This means the last term, 149, is equal to 9 plus some multiple of 4 :
149 = 9 + 4k
140 = 4k
k = 140/4
k = 35
This tells you there are 35 + 1 = 36 terms in the sum (since the first term is 9 plus 0 times 4, and the last term is 9 plus 35 times 4). Among the given options, only the first choice contains the same amount of terms.
Put another way, we have
but if we make the sum start at k = 1, we need to replace every instance of k with k - 1, and accordingly adjust the upper limit in the sum.