Just sub in ANY number for x and solve for y
5x + 7y = 19.....lets say x = 0
5(0) + 7y = 19
7y = 19
y = 19/7...so when x = 0, y = 19/7.....(0,19/7)
5x + 7y = 19....lets say x = 1
5(1) + 7y = 19
5 + 7y = 19
7y = 19 - 5
7y = 14
y = 14/7
y = 2.....so when x = 1, y = 2......(1,2)
5x + 7y = 19.....lets say x = 3
5(3) + 7y = 19
15 + 7y = 19
7y = 19 - 15
7y = 4
y = 4/7...so when x = 3, y = 4/7.....(3,4/7)
I'll be honest, this is a pretty interesting question. I've never seen anything like it before!
We can start off by making equations with the given. If there are 100 heads, that means that the total number of chickens and pigs combined is 100. Thus, we can form our first equation:
p + c = 100
('p' represents number of pigs, and 'c' represents number of chickens)
We also know that there are 270 legs total. Since chickens have 2 and pigs have 4, we can make the following equation:
2c + 4p = 270
I suppose the quickest way to solve for this equation is to use the subtraction method. Put the equations on top of each other:
2c + 4p = 270
c + p = 100
___________
Multiply the bottom equation by -2;
2c + 4p = 270
-2c -2p = 100
____________
"Add" these two equations together:
2c + 4p = 270
-2c -2p = -200
___________
2p = 70
Divide both sides by 2:
p = 35
Ah, finally. Now that we know that there are 35 pigs, input this variable into the first equation to find the number of chickens:
c + 35 = 100
Subtract:
c = 65
There are 35 pigs and 65 chickens
-T.B.
Answer:
16,000 starfish
Step-by-step explanation:
year 0: 1000
year 1: 2000
year 2: 4000
year 3: 8000
year 4: 16000
Answer:
yes
Step-by-step explanation:
Answer: A. divided the difference of the two quantities by the sum of the two quantities.
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Explanation:
The difference of the quantities is 20-15 = 5
The sum of the quantities is 20+15 = 35
Dividing those results leads to 5/35 = 0.142857 which rounds to 0.1429
That converts to 14.29%
This is likely the path Adam took. This path is incorrect. The correct steps are shown below
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Difference = 20-15 = 5
Divide the difference over the original quantity
5/20 = 1/4 = 0.25 = 25%
We have a 25% decrease because the new quantity (15) is smaller than the old quantity (20)
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Here's another way to approach the problem
A = old value = 20
B = new value = 15
C = percent change
C = [ (B-A)/A ] * 100%
C = [ (15-20)/20 ] * 100%
C = (-5/20)*100%
C = -0.25*100%
C = -25%
The negative C value means we have a negative percent change, ie we have a percent decrease. So this is another way to get a 25% decrease.
