Some radioactive isotopes decay at an exponential rate. This decay can be modeled through the function At = A0 e-rt, where At is the mass at any time t, A0 is the original amount, r is the decay rate constant, and t is the time. In addition, each radioactive isotope has a half-life, which is the time it takes for an amount of the material to decrease by half. Using this equation, derive an equation that can be used to calculate the half-life of a certain material.

i think it is 70

step-by-step explanation:

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.

they disappear if your absent from to long. i found out that the hard way.

step-by-step explanation:

brainliest lol i just need one more brainliest.