Can ofloxacin and ceftriaxone be taken together for an e coli urinary tract infection?

Yes. But that is a rather unusual combination of antibiotics for a UTI caused by a single strain of bacteria. Check with your doctor and make certain that is what they want you to take and find out why. If they do not have a good answer get a second opinion. See an infectious diseases expert. There are many in chicago.
Yes. If needed to treat an infection that has numerous organisms that require more than one antibiotic. Otherwise speak to your md as to why you this would need to be done.