Take home pay is equal to blank

What is the pattern in the values as the exponents increase?

Which of these people has balanced their checkbook correctly? oa. gary: the balance in his check register is $500 and the balance in his bank statement is $500. b. gail: the balance in her check register is $400 and the balance in her bank statement is $500. c. gavin: the balance in his check register is $500 and the balance in his bank statement is $510.

Evaluate the expression for the given value of the variable 7a - 4a for a =8