Answer:
50 catfish were put in the pond.
Step-by-step explanation:
Given:
Total Number of fishes in the pond = 75
Let number of catfish be 'c'.
Also Let number of blue gill be 'b'
So We can say that;
Total Number of fishes in the pond is equal to sum of number of catfish and number of blue gill.
framing in equation form we get;
![c+b =75 \ \ \ \ equation \ 1](https://img.qammunity.org/2021/formulas/mathematics/high-school/f6f3orqm8l1xjpe4t3yl3rvnxgqupq69s7.png)
Also Given:
If the number of blue gill was doubled and the number of catfish tripled,there would be 175 fish in the pond.
It means that;
2 multiplied by number of catfish plus 3 multiplied by number of blue gill is equal to 175.
framing in equation form we get;
![2c+3b =175 \ \ \ \ equation \ 2](https://img.qammunity.org/2021/formulas/mathematics/high-school/d5wkvurzg717yebpk0itf4qmdn3pb25r7g.png)
Now Multiplying equation 1 by 2 we get;
![2(c+b) =75*2\\\\2c+2b =150 \ \ \ \ equation\ 3](https://img.qammunity.org/2021/formulas/mathematics/high-school/nxaa8y8ixnztlt56erljnbljvndoshx5yf.png)
Now Subtracting equation 3 from equation 2 we get;
![(2c+3b)-(2c+2b)=175-150\\\\2c+3b-2c-2b=25\\\\b=25](https://img.qammunity.org/2021/formulas/mathematics/high-school/demjlhed12087jtt13pkz258y45x28hhlh.png)
Now Substituting the Value of b in equation 1 we get;
![c+b=75\\\\c+25=75\\\\c=75-25 =50](https://img.qammunity.org/2021/formulas/mathematics/high-school/h0u4rx0vwskqk5fkfzw32ddiisbqodifva.png)
Hence 50 catfish were put in the pond.