Well,properties can help you because you can shorten or make an equation more understandable, like using distributive property in the example 2(5x-3), you can rewrite it as 10x-6. See?
Answer:
Nerys pays 3.1/3.84,5=84,5£per year
Eleri pays 3.84,5=253,5£per year
253,5-84,5=169£ more pay Eleri
A+B+C= 25+25+25=75 so 25 could be your answer
