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Rashid [163]
3 years ago
8

Math short answer question! Please help!

Mathematics
1 answer:
IRISSAK [1]3 years ago
7 0
Part 1:

The circumference of the smaller circle is...
C = 2*pi*r
C = 2*pi*2
C = 4*pi


The circumference of the larger circle is...
C = 2*pi*r
C = 2*pi*8
C = 16*pi


The ratio of the two circumferences is
16*pi:4*pi = 4:1
which means that for every single full rotation of the larger gear, the smaller gear will complete four rotations

If we flip things around, we will have the ratio 4:1 turn into 1:0.25 (divide both parts by 4). Now this says that for every single rotation of the smaller gear, the larger gear rotates 1/4 or 25% of the larger circle circumference. 

1/4 of 360 degrees is 90 degrees

So the larger gear will rotate 90 degrees when the small gear completes a full revolution. 

Answer: 90 degrees

=====================================================

Part 2:

This was pretty much answered in part 1 above. The answer here is 4. The circumference of the larger gear is 4 times larger (since the radius is 4 times larger), so the gear ratio here is 4:1.

Answer: 4

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Find the inverse function y=-5x+20
Nezavi [6.7K]

Answer:

y= \frac{-1}{5} x +4

Step-by-step explanation:

We can find the inverse function of this excercise, isolating X and then changing the variables.

y=-5x+20\\y-20=-5x\\\frac{y-20}{-5} =x\\

\frac{y}{-5}-\frac{20}{-5}  = x\\\frac{-1}{5}y+\frac{20}{5} =x\\ \frac{-1}{5}y+4 =x

And now we change the variables and we get the inverse function:

y= \frac{-1}{5} x +4

7 0
3 years ago
The present age of the father is twice the age of his daughter. Ten years ago, the
Elenna [48]

Answer:

<h3>           The father is 40 and the daughter is 20.</h3>

Step-by-step explanation:

x           -  the present age of the daughter

2x         -  the present age of the fathter  

x - 10          -  the age of the daughter ten year ago

2x - 10        -  the age of the fathter ten year ago

Father is older than his dauther, so:

2x - 10 = (x - 10) + 20  

2x - 10 = x - 10 + 20  

2x - 10 = x + 10              {subtract x from both sides}

x - 10 = 10                      {add 10 to both sides}

x = 20

2x = 2·20 = 40

6 0
3 years ago
F(x) = -4x - 3<br> Evaluate f(9) + f(5)=
RSB [31]

Evaluate f(9) + f(5)= 14f If I didn't answer Your Question fully than tell me please!

7 0
3 years ago
Can somebody help me with this
neonofarm [45]

The sum of the expression (–x² + x) and (x² – 3x – 1) will be –2x – 1. Then the correct option is D.

<h3>What is Algebra?</h3>

The analysis of mathematical representations is algebra, and the handling of those symbols is logic.

The expression can be written as

(–x² + x) and (x² – 3x – 1)

Then the sum of the expression (–x² + x) and (x² – 3x – 1) will be

(–x² + x) + (x² – 3x – 1) = –2x – 1

Then the correct option is D.

More about the Algebra link is given below.

brainly.com/question/953809

#SPJ1

3 0
2 years ago
A survey of an urban university (population of 25,450) showed that 870 of 1,100 students sampled supported a fee increase to fun
Katen [24]

Answer:

95% confidence interval for the proportion of students supporting the fee increase is [0.767, 0.815]. Option C

Step-by-step explanation:

The confidence interval for a proportion is given as [p +/- margin of error (E)]

p is sample proportion = 870/1,100 = 0.791

n is sample size = 1,100

confidence level (C) = 95% = 0.95

significance level = 1 - C = 1 - 0.95 = 0.05 = 5%

critical value (z) at 5% significance level is 1.96.

E = z × sqrt[p(1-p) ÷ n] = 1.96 × sqrt[0.791(1-0.791) ÷ 1,100] = 1.96 × 0.0123 = 0.024

Lower limit of proportion = p - E = 0.791 - 0.024 = 0.767

Upper limit of proportion = p + E = 0.791 + 0.024 = 0.815

95% confidence interval for the proportion of students supporting the fee increase is between a lower limit of 0.767 and an upper limit of 0.815.

5 0
3 years ago
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