Answer:
a)
, b)
, c)
, d) 
Step-by-step explanation:
a) Let assume an initial mass m decaying at a constant rate k throughout time, the differential equation is:

b) The general solution is found after separating variables and integrating each sides:

Where
is the time constant and 
c) The time constant is:


The particular solution of the differential equation is:

d) The amount of radium after 300 years is:

Answer:
a)
, b)
, c)
,
.
Step-by-step explanation:
The volume and the surface area of the sphere are, respectively:


a) The volume of the sphere is:


b) The surface area of the sphere is:


c) The total differentials for volume and surface area of the sphere are, respectively:






Relative errors are presented hereafter:






Answer:
h(3)=n(h_3)×3that is the answer
4y + 228= 352
-228 -228
4y= 124
---- -----
4 4
y=31