Answer:
given a number x, negative 3 times that number is -3x. If this has to be at least 57, it means that -3x must be greater than or equal to 57:
[tex]-3\geq 57[/tex] Dividing both sides by -3 solves the equation, but we have to switch the inequality sign because we're dividing by a negative number:
[tex]x \leq \frac{57}{3} =19[/tex]
