a) \( \left(3.9 \times 10^{9}\right)+\left(6.4 \times 10^{7}\right) \) b) \( \left(8.4 \times 10^{-11}\right)-\left(5.1 \times 10^{-12}\right) \) Give your answers in standard form.

(t) \( \frac{7}{8}-\frac{3}{4}+\frac{5}{16} \)

A nurse is preparing to administer cefazolin 1 g IM . The nurse reconstitutes a 1 g vial of cefazolin with sterile water to yield a final concentration of \( 330 \mathrm{mg} / \mathrm{mL} \). How many mL should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)

A nurse is preparing to administer tobramycin \( 4 \mathrm{mg} / \mathrm{kg} / \) day IM divided in three equal doses to a client who weighs 60 kg . Available is tobramycin \( 40 \mathrm{mg} / \mathrm{mL} \). How many mL should the nurse administer per dose? (Round the answer to the whole number. Use a leading zero if it applies. Do not use a trailing zero.)

\( 25+|(-9)-(-7)||| \)

8. Juan debe 160 € en la charcutería. Cuatro de sus amistades quieren ayudarlo, dándole 20 euros cada uno. ¿Qué deuda tiene Juan ahora?