A formula for determining the finite sum, S, of an arithmetic sequence of numbers is S = (a + b), where n is the number of
terms, a is the first term, and b is the last term. Express b in
terms of a, S, and n.
PLEASE HELP ME!!!

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

What is the order of these fractions from least to greatest 2/3 7/10 5/8 65/100

Janice determined there were 10 possible outcomes when tossing two coins and spinning a spinner numbered 1 through 6. what is the correct number? what might have been janice's error?