Let L and C equal the number of pages that are read by Li Wei and Colleen respectively.
L=90+30h
C=126+24h
They will have read the same number of pages when L=C so we can say:
90+30h=126+24h subtract 90 from both sides
30h=36+24h subtract 24h from both sides
6h=36 divide both sides by 6
h=6 hours
So after 6 hours of reading they will both be on the same page.
