A couple of students worked in tandem

[alpacinou]

Hello.

Have I used "in tandem" correctly and naturally? Is it okay to use it after teamwork?

When I was in a school, I worked with my classmates to solve a problem. It was teamwork by a couple of students working in tandem that made the difference and resulted in that problem being solved.

 

[GoesStation]

"Working together" is simpler.

 

[alpacinou]

"Working together" is simpler.

I know, but is my sentence okay?

 

[GoesStation]

I know, but is my sentence okay?

It's not terrible, but simpler is usually better.

 

[tedmc]

When I was in a school, I worked with my classmates to solve a problem. It was teamwork by a couple of students working in tandem that made the difference and resulted in that problem being solved.

Since you have said it is teamwork, the underlined part means the same thing and could be omitted.