What is the common difference of 31, -169, -369, -569?

31 is a positive number, while -169, -369, and -569 is negative.

Step-by-step explanation:

Negative numbers, are numbers less then 0 and include a negative sign that looks like this "-".

Positive numbers are numbers above 0 and don't include a negative sign.

-169, -369, and -569 is negative because they have a negative symbol and the number is below 0, while 31 is positive because it's above 0 and doesn't include a negative sign.

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

there would only be 50 odd numbers between 1 and 100 so therefor there would be 50 even so that would only be 50 odd numbers.