This system of equations is shown in the graph. y=3x-4, y=2/3x+1. Estimate the solution by approximating which two integer values the coordinates of the intersection point lie between

step-by-step explanation:

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

source:  

the answer is  

c.

14,469 cubic feet

i know this one is right