What is the value of “r” if
2080m cubed =. pi x r squared

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

Darcy deposited $390 into a savings account. as long as the account balance remains at or above $150, she does not have to pay a service fee for the account. for how many months can she withdraw $40 a month without having to pay service fees? a) 3 b) 5 c) 6 d) 9

Gabrielle's age is three times mikhail's age. the sum of their ages is 40 . what is mikhail's age? __ years old