91Ó°ÊÓ

Two numbers with similar signs get added and the resulting number carries the similar sign.

Two numbers with opposite signs get subtracted and the resulting number carries the sign of the larger number.

One-part ethylene glycol with three-part water solution(1) has $-12{}^{∘}C$ freezing point whereas another solution(2) with two parts ethylene glycol and two parts water has $-36{}^{∘}C$freezing point

To check how much lower the temperature of the solution 1 is as compared to solution 2

The difference is calculated as,

$-36-\left(-12\right)$ [ one elementary bracket operation]

$=-36+12$ [Bracket removed and negative signs multiplied]

$=-24{}^{∘}C$

Therefore, the answer is $-24{}^{∘}C$

Solution 1 has the lower temperature and it is $-24{}^{∘}C$lower than solution 2