Sam bought 2 model airplanes and 6 toy cars. he paid $17 total. marissa bought 2 model airplanes and returned 10 toy cars. she paid $9 total. a system of equations that represents their purchases and returns is shown below, where x represents the cost of a model airplane and y represents the cost of a toy car. 2x+6y=17 2x-10y=9 select the equations that could represent 2x+6y=17 and still produce the same answer to the system of equations, if 2x+(-10y)=9 were multiplied by 2 and added to 2x+6y=1 a. 6x-14y=35 b. 4x+12y=-34 c. x-16y=26 d. -2x+26y=-1