To check for a blockage in a patient's veins, 2.25 ml of a radioactive liquid with a half-life of 2.2 hours is injected into the patient's blood stream. If the liquid is administered at 7:00 am, at what time will the amount of the liquid decrease to 0.41 ml?

i hope this is what you were looking for.

see attached graph

part a: 1.08

part b: 27.59

the image is given below

since the options are not given so we draw it from the equation

the given equation is

y = (x-1) (x+4)

y = y² + 3x - 4

the above equation is a quadratic equation which will have two roots. if we draw the graph for it, it will look like this

the given 6 = w/p is equivalent to 6p = w, where w is the total area of the walls and p is the area covered by a single can of paint.

knowing that 6 cans of paint will be needed, 6p = w becomes 6(6) = w = 36.   this tells us that the total area to be painted is 36 square units.