Does it imply that if the funding agency provides X amount, the recipients (either academic or industrial) should match that amount with 1.5×X
Yes, that's likely what co-financing means. Co-financing means that there is a requirement that recipients of the funds (or, more accurately, their employers) are expected to contribute a certain amount of resources themselves. This can be either in money or through "in-kind" contributions, for instance staff dedicated to the project.
That said, the details of such co-funding agreements vary (and are very important). I don't speak Danish, so I can't say how your call specifically works, but questions you should resolve before applying include:
- Is co-funding required for academic partners, industry partners, or both ? It's common to have a different co-funding requirement for different types of partners (not rarely with a co-funding rate of 0% for universities).
- Is co-funding calculated across the entire project volume, or per partner? Is it ok if one partner contributed 2X and another partner 0X as long as it's >= 1.5X overall?
- What kind of co-funding is required? Does staff delegated to the project count? Do software licenses count?
- How strict are they in checking co-funding requirements after the project ends? Will you be in trouble / will you need to reimburse money if your project ends up using too much of the funded money and too little of the co-funding / in-kind contributions?
All in all, I recommend that you talk with your economist or somebody else in your institution with experience with this call before handing in your proposal.