A particular Chemistry book costs $6 less than a particular Physics book. Two such Chemistry books

Question

and three such Physics books cost a total of $123. Construct two simultaneous equations and solve
them using the substitution method. Show your working.

I just need help constructing the simultaneous equations. I should be fine with solving them, thank you :)

Answer 1

Just turn the words into math.

A particular Chemistry book costs $6 less than a particular Physics book
c = p-6

Two Chemistry books and three Physics books cost $123
2c+3p = 123

now substitute and crank it out

Answer 2

Thank you :)