You can put this solution on YOUR website! This system,
0.6x - 0.2y = -0.2
-0.03x - 0.07y = 0.17
will be a bit more comfortable if you multiply the entire first equation by 10, and the entire second equation by -100.
You will then have the equivalent system,
6x-2y=-2
3x+7y=-17
Solve either equation for x OR y; substitute the found expression into the other equation and solve for the other variable. You now will have one of the values for that variable.
As example of a way to do the process, I pick the second equation and solve for y:
7y=-17-3x
y=(-17-3x)/7
Let me put this expression for y into the first equation.
6x-2(y)=-2
6x-2((-17-3x)/7)=-2
OR
Now solve for x,.....continue until done....!
... a little bit further into the process,
clear the fraction by multiplying both sides by 7: , ...... You can continue on from here...