Chapter 1.1, Problem 54E

Solve the system of equations: {x+2y+6z=5x+y2z=3x4y2z=1 .

The Federal Helium Reserve held about 16 billioncubic feet of helium in 2010 and is being depleted byabout 2.1 billion cubic feet each year. a. Give a linear equation for the remaining federalhelium reserves, R, in terms of t, the number of years since 2010. b. In 2015, what will the helium reserves be? c. If the rate of depletion doesn’t change, in what year will the Federal Helium Reserve be depleted?