Simplify both sides if needed. The left-hand side needs simplification.
4(x - 6)

-2x + 6
4x - 24

-2x + 6
All is left to do is add and subtract to get the x variable all alone.
4x - 24

-2x + 6
6x - 24

6 <-- Add 2x to both sides
6x

30 <-- Add 24 to both sides
x

5 <-- Divide both sides by 6
In order to be in the solution set, x has to be less than or equal to 5.
In interval notation: [5, -∞)
select two points on the line, and plug into this formula y2-y1 over x2-x1
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:
Area of a square = side * 4
Step-by-step explanation: