Algebra

We can write   these two equations

2x - 9y   = 14     (1)

8x - 42  = y        (2)

Sub (2)  into (1)

2x - 9(8x - 42)  = 14

2x - 72x + 378  = 14

-70x  = 14 - 378

-70x = -364

x = -364 / -70  =  26/5 =  5.2

y = 8 (5.2) -42  =  -0.4

xy  =  (5.2) (-0.4)   =  -2.08

No, C Phill's answer is correct. 

By graphing the system, we find that the solution for the system is (5.2, -0.4), and \(5.2 \times -0.4 = \color{brown}\boxed{-2.08}\)