Kiersten runs a website that people learn programming. every month, kiersten receives a subscription fee of \$10$10dollar sign, 10 from each of the subscribers to her website. last month, the website had 100100100 subscribers. this month, 303030 new members joined the website, and 101010 members cancelled their subscription. how much money will kiersten’s online business earn this month?

The multiplicative property of equality states that for real numbers a, b, c, and d, if a = b and c = d, then ac = bd. true false

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?