20. Find param 1 given param 2.

| param1 | param2 | Answer |
| :---: | :---: | :---: |
| maximum $2 x+y$ | $\|4 x-3 y\|+5 \sqrt{x^{2}+y^{2}-20 y+100}=30$ |  |
| maximum $x+2 y$ | $\|4 y-3 x\|+5 \sqrt{x^{2}+y^{2}+20 y+100}=40$ |  |
| maximum $2 y-x$ | $\|4 y+3 x\|+5 \sqrt{x^{2}+y^{2}+10 x+25}=15$ |  |
| maximum $x-5 y$ | $\|5 x-12 y\|+13 \sqrt{x^{2}+y^{2}-26 y+169}=156$ |  |
| minimum $y-5 x$ | $\|5 y-12 x\|+13 \sqrt{x^{2}+y^{2}+26 x+169}=156$ |  |
20. Find param 1 given param2.

| param1 | param2 | Answer |
| :---: | :---: | :---: |
| maximum $2 x+y$ | $\|4 x-3 y\|+5 \sqrt{x^{2}+y^{2}-20 y+100}=30$ | 16 |
| maximum $x+2 y$ | $\|4 y-3 x\|+5 \sqrt{x^{2}+y^{2}+20 y+100}=40$ | -12 |
| maximum $2 y-x$ | $\|4 y+3 x\|+5 \sqrt{x^{2}+y^{2}+10 x+25}=15$ | 8 |
| maximum $x-5 y$ | $\|5 x-12 y\|+13 \sqrt{x^{2}+y^{2}-26 y+169}=156$ | -5 |
| minimum $y-5 x$ | $\|5 y-12 x\|+13 \sqrt{x^{2}+y^{2}+26 x+169}=156$ | 5 |