This is really confusing me:
simplify so that your answers contain only positive exponents.

In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.

Emmanuel has had a sharps exposure at work and has reported the incident, his employer has offered him an immediate confidential medical evaluation and follow-up care. what can he expect from the exam?

Determine if the situation below is a safe practice: julia needs to hang some industrial shelving, so she carefully selects the correct drill bits for the electrical drill before attempting to screw the shelves into the wall.