It takes two to tango. 손바닥도 마주쳐야 소리가 난다.

It takes two to tango

"It takes two to tango"는 상황이나 문제에 관련된 두 사람 모두 책임이 있음을 의미합니다. 춤과 마찬가지로 두 파트너가 함께 참여하고 협력해야 성공할 수 있습니다. 한 사람만 노력하면 잘 되지 않지요 그래서 일이 잘 되려면 양쪽의 협력과 노력이 필요하다는 의미예요. 

손바닥도 마주쳐야 소리가 난다.

"It takes two to tango" means that both people involved in a situation or problem are responsible for it. Just like in a dance, both partners need to participate and work together to make it successful. If only one person is trying, it won't work out well. So, it's a way of saying that cooperation and effort from both sides are needed to make things work.

when two people work as a team, they are both responsible for the team's successes and failures.