You drink a beverage with 120 mg of caffeine. each hour, the caffeine in your system decreases by about 12%. how long until you have 10mg of caffeine?

  19.44 hours, about 19 hours 26 minutes

Step-by-step explanation:

The exponential equation that describes your caffeine level can be written as ...

  c(t) = 120·(1 -0.12)^t . . . . where t is in hours and c(t) is in mg

We want to find t for c(t) = 10, so ...

  10 = 120(0.88^t)

  10/120 = 0.88^t . . . . . . . divide by 120

  log(1/12) = t·log(0.88) . . . take logarithms

  t = log(1/12)/log(0.88) ≈ 19.4386

It will take about 19.44 hours, or 19 hours 26 minutes, for the caffeine level in your system to decrease to 10 mg.

correct answer is infinitely many solutions

step-by-step explanation:

2(2x + 3) = -4 + 2(2x + 5)

solving the above equation:

4x + 6 = -4 +4x +10

combining like terms

4x -4x = -4+10-6

0=0

since both sides are 0=0, we end up into true statement it means it has infinite many solutions.

so correct answer is infinitely many solutions

70

step-by-step explanation: