Put two and two together: figure something out; reason from the facts.
結論を導く、分かる、事実からの結論

George: I'm trying to figure out this math problem, but can't seem to put two and two together. 

Sam: Have you tried to another formula?

ジョージ：この数学の問題の答えを出そうとしているんだけど、答えが出ないみたいなんだ

サム：他の計算式でやってみたの？