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kotykmax [81]
3 years ago
7

In a field of ducks and a dog someone counted 25 heads and 80 legs. How many dogs and ducks are there

Mathematics
2 answers:
Anni [7]3 years ago
8 0
Ducks have two legs while dogs have four legs and their are 25 heads, so there must be 15 dogs and 10 ducks.
15(heads) x 4(legs/head) = 60 legs      10 (heads) x 2 (legs/head) = 20 legs
                                      60 legs + 20 legs = 80 legs
                                      15 heads + 10 heads = 25 heads
(legs/head) is read as legs per head
brilliants [131]3 years ago
6 0
Ducks have 1 head. Dogs have 1 head.
Ducks have 2 feet. Dogs have 4 feet.

If x = no. of ducks and g = no. of dogs

x + g = 25
2x + 4g = 80

Let's use substitution to solve.

x + g = 25 ⇒ x = 25 - g
replace x with 25 - g in the other equation and solve for g

2x + 4g = 80
2(25 - g) + 4g = 80
50 - 2g  + 4g = 80
50 + 2g = 80
2g = 30
g = 15

Now use g = 15 in an earlier equation to find x.

x + g = 25
x + 15 = 25
x = 10
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lapo4ka [179]
Perhaps the easiest way to find the midpoint between two given points is to average their coordinates: add them up and divide by 2.

A) The midpoint C' of AB is
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The midpoint B' is
.. (A +C)/2 = ((0, 0) +(p, 0))/2 = (p/2, 0) = B'
The midpoint A' is
.. (B +C)/2 = ((m, n) +(p, 0))/2 = ((m+p)/2, n/2) = A'

B) The slope of the line between (x1, y1) and (x2, y2) is given by
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Using the values for A and A', we have
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C) We know the line goes through A = (0, 0), so we can write the point-slope form of the equation for AA' as
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.. y = n*x/(m+p)

D) To show the point lies on the line, we can substitute its coordinates for x and y and see if we get something that looks true.
.. (x, y) = ((m+p)/3, n/3)
Putting these into our equation, we have
.. n/3 = n*((m+p)/3)/(m+p)
The expression on the right has factors of (m+p) that cancel*, so we end up with
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3 years ago
Mischa wrote the quadratic equation 0 = –x2 + 4x – 7 in standard form. What is the value of c in her equation
Zolol [24]

Mischa wrote the quadratic equation 0 = –x2 + 4x – 7 in standard form

The standard form of quadratic equation is

y= ax^2 + bx + c

When y=0 then the standard equation becomes

0= ax^2 + bx + c

Now we compare the given equation 0 = -x^2 + 4x - 7  with 0= ax^2 + bx + c and find the value of a, b,c

-x^2 can be written as -1x^2

0= ax^2 + bx + c

0 = -1x^2 + 4x - 7

a= -1 , b=4  and c=-7

The value of c is -7

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Sophia has $91,000 in a savings account that earns 7% annually. The interest is not compounded. To the nearest cent, how much wi
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Answer:

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