If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds?
a. one-fourth
b. half
c. one-eighth
d. you would need to know how many atoms you are starting with.

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0

Raymond just got done jumping at super bounce trampoline center. the total cost of his session was $43.25 . he had to pay a $7 entrance fee and $1.25 for every minute he was on the trampoline. write an equation to determine the number of minutes (t) that raymond was on the trampoline.