When both sides of the inequality are multiplied or divided by the same nonzero constant, the direction of the inequality is preserved if the constant is positive but the direction is reversed if the constant is negative. In either case, the new inequality is equivalent to the original.
Ex. The inequality can be solved as follows.
(5 subtracted from both sides)
(both sides divided by -3, which reverses the direction of the inequality)
Therefore, the solution set of consists of all real numbers greater than or equal to –4.