Answer:
32 degrees
Step-by-step explanation: So they tell you BE is congruent to BC so triangle BCE is isosceles. We know that angle C is 35 degrees and the triangle is isosceles so angle E is 35 degrees too. Now we do 180-(35+35) and that equals 110 so angle B is 110. And we know that angle EBC and FBA are supplementary angles so 180-110 is 70 degrees so angle FBA is 70 degrees and you can do the same thing with angle DFB and AFB so 180-102 degrees is 78 degrees and to find angle a you just do 180-(70+78) and that equals 32 degrees so angle A is 32 degrees. :)
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:
The correct answer is the last option:) hope u get an 100%!
