Negative three times a number is at least 57.
a.–3n 2 57; {m\n 5-19)
b. –3n 57, 7|12-19
c. –3n 2 57, {m\n 5 19}
d. -32 > 57, (n\n< -19}

The option formatting isn't very clear, anyway: 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:

Dividing both sides by -3 solves the equation, but we have to switch the inequality sign because we're dividing by a negative number:

each side has a different length.  

step-by-step explanation:

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950