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.

The expression 6x2 gives the surface area of a cube, and the expression x3 gives the volume of a cube, where x is the length of one side of the cube. find the surface area and the volume of a cube with a side length of 6m

Is it greater than or less than7*3_9*2

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?