One pipe can empty a tank in 45 minutes while a second pipe can empty it in 60 minutes. If both pipes are opened at the same time, how long will it take to drain the tank?

Mary had at least an 80% on her test write an inequality to represent this situation

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60

In which direction does the left side of the graph of this function point? a(x) = 3x - x2 + 4x - 2