1 | initial version |

You are using "implicit multiplication" which Sage does not understand by default (you can turn it on if you want). You should change `2y`

above to `2*y`

and `80(3200-x-y)`

to `80*(3200-x-y)`

, etc... Here is code that works:

```
x, y = var('x, y')
solve([20*(6400-x-2*y)==0, 80*(3200-x-y)==0], x, y)
```

Sage's output is:

```
[[x == 0, y == 3200]]
```

ps. Implicit multiplication can be turned on using: `implicit_multiplication(True)`

, see the preparser documentation.

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