It's a Deal
Meaning/Usage: Agreeing on a proposal
Explanation: Commonly used by itself when agreeing to a proposal made by someone.
1-So if I take the kids to swim lessons, you will clean the house? It's a deal!
2-It's a deal. I will clean the garage if you stop bothering me about it.
3-If I stop eating donuts, I don't have to run every day? It's a deal!
Conversation
A-If you do my yard work, I will buy you candy.
B-No thanks. I shouldn't eat too much candy.
A-If you mow my grass, I will pay you ten dollars.
B-Sounds good. It's a deal.
Other Common Sentences
1-I agree to your proposal.
2-Let's agree to that.