You can put this solution on YOUR website! In a proportion, you're basically doing the opposite of simplifying a problem, you're expanding it. When you see one, think to yourself: "Two over five is the same as four over what?"
2/5=4/n
1. Cross-multiply.
2n=20
2. Divide both sides by the number next to the variable(the letter) to get the variable alone.
n=10
There's your answer!
You know this is right because if you multiply 2/5 by 2, it equals 4/10.
