If I remember correctly this is how you solve it.
f(x)=8x+6
f(-1)=8(-1)+6
f(-1)=-8+6
f(-1)= -2
This is an arithmetic sequence with a common difference of -4, meaning that each term is four less than the previous term. So the next term in that sequence (technically the term "series" should be reserve for infinite sequences) will be 67-4=63.
What fraction of the length is the width of the book
is 2:3
To make the equation true the value of c has to equal -5/3