Answers:
- Total equation: x+y = 80
- Legs equation: 2x+4y = 248
- How many ducks? 36
- How many cows? 44
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Further explanation:
- x = number of ducks
- y = number of cows
x+y = 80 is the total equation (ie the head count equation) since we assume each animal has 1 head, and there are 80 heads total.
That equation can be solved to y = 80-x after subtracting x from both sides.
The legs equation is 2x+4y = 248 because...
- 2x = number of legs from all the ducks only
- 4y = number of legs from all the cows only
- 2x+4y = total number of legs from both types of animals combined
We're told there are 248 legs overall, so that's how we ended up with 2x+4y = 248
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Let's plug y = 80-x into the second equation and solve for x.
2x+4y = 248
2x+4( y ) = 248
2x+4( 80-x ) = 248
2x+320-4x = 248
-2x+320 = 248
-2x = 248-320
-2x = -72
x = -72/(-2)
x = 36
There are 36 ducks
Now use this x value to find y
y = 80-x
y = 80-36
y = 44
There are 44 cows.
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Check:
36 ducks + 44 cows = 80 animals total
36*2 + 44*4 = 72 + 176 = 248 legs total
The answers are confirmed.
Answer:
a) 1/800 or 0.00125
b) i) 0.0013
ii) 0.001
c) 60%
Step-by-step explanation:
T = [tan(2×30)+1][2cos(30)-1] ÷ (y²-x²)
T = (tan60 + 1)(2cos30 - 1) ÷ (41² - 9²)
T = (sqrt(3) + 1)(sqrt(3) - 1) ÷ 1600
T = (3-1)/1600
T = 2/1600
T = 1/800
T = 0.00125
Error: 0.002 - 0.00125
0.00075
%error
0.00075/0.00125 × 100
60%
From calculus, to determine the maxima or minima of the graph, get the derivative of the equation and equate to zero. So, we derive first the equation of the graph and equate to zero.
C = 0.25x² - 80x + 30000
dC/dx = 0 = 0.5x - 80 + 0
0.5x = 80
x = 80/0.5
x = 160 units
The minimum cost (although not asked) is:
C = 0.25(160)² - 80(160) + 30000
C = $23,600
The answer is 160 units.
50 might be the answer because 12÷6=2 so I just multiplied 15×2 and that equaled my answer, 50
Answer:
x=y
Step-by-step explanation:
Answer: The equation for the line of reflection will be x = y.
