Aquariums 80526

Mirko has a total of 137 fish in three aquariums. He has 19 more fish in the largest aquarium than in the medium. There are 5 fewer fish in the smallest than in the middle one. How many fish does Mirko have in the smallest aquarium?

Correct answer:

c =  36

Step-by-step explanation:

$$\begin{gathered} a+b+c=137 \\ a=19+b \\ c=b-5 \\ a+b+c=137 \\ a-b=19 \\ b-c=5 \\ Row2-Row1\to Row2 \\ a+b+c=137 \\ -2b-c=-118 \\ b-c=5 \\ Row3-\frac{1}{-2}\cdot Row2\to Row3 \\ a+b+c=137 \\ -2b-c=-118 \\ -1.5c=-54 \\ c=\frac{-54}{-1.5}=36 \\ b=\frac{-118+c}{-2}=\frac{-118+36}{-2}=41 \\ a=137-b-c=137-41-36=60 \\ a=60 \\ b=41 \\ c=36 \end{gathered}$$

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