Years of decay...
It takes around 4 years for something to go through their half life (depending on the thing). This chart is showing the years go by (half lives that occur within the years) while the decaying is happening.
Answer:

Step-by-step explanation:
The slope-intercept form of an equation of a line:

m - slope
b - y-intercept
The formula of a slope:

We have the points M(5, 5) and N(-10, -19). Substitute:

We have the equation:

Put the coordinates of the point M to the equation:

<em>subtract 8 from both sides</em>

Finally we have the equation:
