Question

the melting point of mercury is about 1/4 of the melting point of krypton. the melting point of mercury is -39°C. Write and solve an equation to find the melting point of krypton. would K-1/4= -39° Work?

Answer 1

This is not the best question I've ever seen. The wording is the problem, and it's not your fault. The melting point of Krypton is about - 160 oC. It means that numerically the melting point of Krypton is 4 times lower than that of mercury.

Krypton = 4*M

M = - 39

Krypton = 4*-39

Krypton = - 156o C

Now you want to make it something like K(1/4) = - 39 which would be fine. You can't use - 1/4. If you do, your answer will come out to be + 156 which is not what you mean. If this was a multiple choice question, your answer would be the second best one.