Answer:
5 and 24
Step-by-step explanation:
1) replace the x's with 125 | c(x)=120+4(125)/(125)
620/125=5 simplify numerator
x=5
2) replace c(x) with 9 | 9=120+4x/x
9x=4x+120 multiply both sides by x
9x-4x=4x+120-4x subtract both sides by -4x
5x=120 divide both sides by 5
x=24
so, it costs about 5 dollars per book when 125 are printed
and, if it costs 9 dollars per book, 24 should be printed