## College Algebra (10th Edition)

$23$ commercial launches, $58$ noncommercial launches.
Let $x=$ the number of commercial launches and $y=$ the number of noncommercial launches. Given:$\left\{\begin{array}{ll} x+y=81 & (1)\\ y=2x+12 & (2) \end{array}\right.$ Substitute y from ($2$) into ($1$) $x+y=81$ $x+(2x+12)=81$ $3x+12=81$ $3x=69$ $x=23$ Back-substitute into ($2$) $y=2(23)+12=58$ $23$ commercial launches, $58$ noncommercial launches.