1. First you multiply by 10 to get rid of the decimals
3x - 5y = 12 and 7x - 2y = -1
2. Since we need to solve by elimation, we want to elimanate a variable. To do that multiple the first equation by 2 and the second equation by -5
6x - 10y = 24
-35x +10y = 5
3. Add the equations downwards
-29x = 29
4. Divide both side by -29
x= -1
5. Solve for y by putting -1 in for x into any of the equations. I'll use 3x- 5y=12
3(-1) -5y = 12
-3-5y=12
-5y =15
y= -3