The half-life of rubidium-89 is 15 minutes. If the initial mass of the isotope is 250 grams, how many grams will be left after 100 minutes?

The system of equations {y=4x} {y-4=4 (x-1) what solution does it has.

449/0.42 nearest tenth

1. Paige was assigned some math problems for homework. She solved the first 32 of the problems before dinner. She finished the last 20% of the assignment after dinner. How many math problems was Paige assigned? A. 36 B. 38 C. 40 D. 160

Castor brought 6 3/4 small carrot cakes to share with the 26 students in class did Castor bring enough for each student to have 1/4 of a cake? explain your thinking

Solve the proportion P/6 = 24/36

How do I simplify 9/243

How far does Gerry live from school

Percent sales tax: 7% price before tax: $250 price with tax:

Can you show the work to 156 divide by 11

Which expression is equivalent to a + (c + 7) ? 7 a c a minus (c + 7) (c + 7) minus a (a + c) + 7