These are not similar. For them to be similar, they need to exist in proportion to each other for every single side. The ratio of the 12:9 sides is 4:3 when reduced. The ratio of the other 2 sides is 5:3. They all have to have the same ratio for them to be similar.
There is no solution to this set that works for both equations. If you multiply the top equation by 2 and then add them together, the x and y numbers will cancel. This leaves you with 0 =1010, which is never true.
