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Rudik [331]
3 years ago
9

Dan is watching The Birds in his backyard. Of the birds he watches, 9. Of them,or 45%, are sparrows. How many birds are in his b

ackyard?
Mathematics
1 answer:
ra1l [238]3 years ago
5 0

If 9 of the sparrows is 45% of the birds in the backyard, 9/x = 45/100.

Cross multiply to get 9 * 100 = 45x; simplified is 900 = 45x or 20.

This means that there are 20 birds in the backyard. You can check this by dividing 9/20 which equals 45%

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Find the recursive rule, explicit rule, and f(20)
DiKsa [7]

Answer:

Recursive:

f(1)=35, f(n)=f(n-1)+10

Explicit:

f(n)=35+10(n-1)

And the 20th term is 225.

Step-by-step explanation:

We have the sequence:

35, 45, 55, 65.

Notice that each subsequent term is 10 more than the previous term.

Therefore, our common difference is (+)10.

Recursive Rule:

The standard format for the recursive rule is:

f(n)=a, f(n)=f(n-1)+d

Where a is the initial term and d is the common difference.

From our sequence, we know that a the initial term is 35.

And as determined, our common difference d is 10.

Substitute. Hence, our recursive rule is:

f(1)=35, f(n)=f(n-1)+10

Explicit Rule:

The standard format for the explicit rule is:

f(n)=a+d(n-1)

Where a is the initial term and d is the common difference. So, let’s substitute 35 for a and 10 for d. Hence, our explicit formula is:

f(n)=35+10(n-1)

Now, let’s find the 20th term. We will utilize the explicit rule since the recursive rule can get tedious. Substitute 20 for n because we would like to 20th term. Thus:

f(20)=35+10(20-1)

Evaluate:

\begin{aligned} f(20)&=35+10(19) \\ f(20)&=35+190 \\ f(20)&=225 \end{aligned}

Hence, the 20th term is 225.

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3 years ago
Eight bungee cord for $10 or 20 bungee cords for $20
ICE Princess25 [194]

20 bungee cords for $10

6 0
3 years ago
What is the expression written using each base only once?
Murrr4er [49]
1. (-4)^-6 * (-4)^7 = (-4)^(-6+7) = (-4)^1 =
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3 years ago
Hint: Plug each number into the formula a^2 + b^2 = c^2. Then see which set of numbers balances out.
Anni [7]

Answer:

A

Step-by-step:

a^2+ b^2 = c^2

if we try A

6^2+8^2 = 10^2 => 64+36  = 100

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2 years ago
Solve for w in the proportion.
Svet_ta [14]

Answer:

w=40

Step-by-step explanation:

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3 years ago
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