Para calcular mentalmente 35 x 12 y 45 x 18. Ana descompone el 12 y el 18 y distribuye. 35 x 12= 35 x (10+2) = 35 x 10 + 2 x 35 = 420 45 x 18 = 45 x (20-2) = 45 x 10 - 45 x 2 =810 Usa un método similar para calcular los productos siguientes: 1.504 x 20= 189x9= de paso expliquen q no entendi un pepino jajs xfavor y gracias xde

The mean of a set of data is -3.82 and its standard deviation is 2.31. find the z score for a value of 3.99.

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

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