I need to compute this on matlab Metronidazole used to treat

I need to compute this on matlab.

Metronidazole (used to treat infections) has a half life of H = 7.9 hours. Use solve to calculate [5 pt]
the amount of time it takes for 50mg to decay to 20mg. Note that the decay constant is ? ln(2)/H.
Assign the answer to p5.

Solution

giving:

So the concentration has reached the 20mg level at 10.4 hours.