△def is rotated about point n to △d′e′f′ . which statements are true about the pre-image and image? select each correct answer. dn¯¯¯¯¯¯≅d′n′¯¯¯¯¯¯¯¯ the corresponding side lengths in the image and the pre-image are not equal. all corresponding points on the image and pre-image are equidistant to point n. the image is the same size and shape as the pre-image.

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

What is the result of the following division?

The measures of the legs of a right triangle are 15m and 20m . what is the length of the hypotenuse