A math class is having a discussion on how to determine if the expressions 4x-X+5 a substitution. The class has suggested four different methods.
Which describes the correct method?
Both expressions should be evaluated with one value. If the final values of the expre
two expressions must be equivalent.
Both expressions should be evaluated with one value. If the final values of the expre
two expressions must be equivalent.
Both expressions should be evaluated with two different values. If for each substitute
expressions are positive, then the two expressions must be equivalent.
Both expressions should be evaluated with two different values. If for each substituted
expressions are the same, then the two expressions must be equivalent.

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

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults. how many students and adults went if the ticket charge was $42.75

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.