\(-5 \le -2\); Add 7 to both sides

\(-6 \lt -3\); Divide both sides by -3

\(7 \gt -4\); Subtract 7 from both sides

\(-1 \ge -8\); Multiply both sides by -2

\(\text{n} - 5 \ge -2\)

\(3 + \text{x} \lt 7\)

\(-7\text{y} \le 14\)

\(\frac{\text{b}}{5} \gt -1\)

For a scientific experiment, a physicist must make sure that the temperature of a metal at 0 °C gets no colder than -80 °C. The physicist changes the metal’s temperature at a steady rate of -4 °C per hour. For how long can the physicist change the temperature?

a. Let t represent temperature in degrees Celsius. Write an inequality. Use the fact that the rate of change in temperature times the number of hours equals the final temperature.

b. Solve the inequality in part a. How long can the physicist change the temperature of the metal?

c. The physicist has to repeat the experiment if the metal gets cooler than -80 °C. How many hours would the physicist have to cool the metal for this to happen?

Suppose you are solving an inequality. Under what circumstances do you reverse the inequality symbol?