Answer:
or 
Step-by-step explanation:
We can convert from mixed numbers to decimal numbers:

Since they cleaned up 8.2 kilograms of trash in one neighborhood and 11.5 kilograms in another neighborhood, the total trash they cleaned up was:

We know that they sent 1.25 kilograms to be recycled. Then, in order to calculate how many kilograms of trash they threw away, we must subtract the total kilograms of trash they cleaned up and the kilograms they sent to be recycled.
Then:
or 
This is a combination problem. The approach to this is by using the nCr method, where n is the number of total objects and r is the number of success. For example, if you want to get 3 red out of the total 4, then that would be 4C3. That means,
4C3 = 4!/3!(4 - 3)! = 4 ways
If you want to get 2 green out of the total 6, then that would be 6C2. That means,
6C2 = 6!/2!(6-2)! = 15 ways
Therefore, there are a total of 4+15 = <em>19 ways</em>.
(-3 - 2i) x (-4+ 2i) if you simplify using FOIL you will get 16+2i
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Assumptions
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Let x be the amount of 25% orange juice
Let y be the amount of 10% orange juice
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There are 15 litres of 13% orange juice
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x + y = 15
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The 15 litres of juice is 13% orange juice
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0.25x + 0.1y = 15 x 0.13
0.25x + 0.1y = 1.95
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Rewrite the equations and solve for x and y
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x + y = 15 ----------------------- (Equation 1)
0.25x + 0.1y = 1.95 ----------- (Equation 2)
(Equation 1):
x + y = 15
x = 15 - y ----------- (Substitute into Equation 2)
0.25 (15 - y) + 0.1y = 1.95
3.75 - 0.25y + 0.1y = 1.95
0.15y = 1.8
y = 18 ÷ 0.15
y = 12 ------------- (substitute into Equation 1)
x + y = 15
x + 12 = 15
x = 15 - 12
x = 3
x = 3 and y = 12
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Answer: 3 liters of 25% of orange juice with 12 liters of 10% orange juice
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$70 into 1:2:4
1+2+4 = 7
7 parts= $70
1 part = $70/7 ($70 divided by 7)
1:2:4 = $10:$20:$40
answer= $10:$20:$40
Hope this helps!! :)