Which equation can be used to find the measure of angle lkj? cos−1(startfraction 8.9 over 10.9 endfraction) = x cos−1(startfraction 10.9 over 8.9 endfraction) = x sin−1(startfraction 10.9 over 8.9 endfraction) = x sin−1(startfraction 8.9 over 10.9 endfraction) = x

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

Apublic library wants to place 4 magazines and 9 books on each display shelf. the expression 4s+9s represents the total number of items that will be displayed on s shelves. simplify the expression

Michelle is planting flowers in her garden. she wants the ratio of daises to carnations to be 3 to 2. michelle wants to plant a total of 35 flowers. how many daises should she plant?