Lets substitute for each variable, then solve:- x = 13.2 y = 4.3 x = 13.2 -13.2 - 2y y = 4.3 -x - 2 · 4.3 Lets solve:- -13.2 - 2 × 4.3  -13.2 - (2 × 4.3) -13.2 - 8.6 -21.8 So, when x = 13.2 and y = 4.3, -x - 2y = -21.8 Hope I helped ya!! xD