Odalys ordered mulch and river rock, which cost a total of 342,forherhome.Thegivenequationrepresentstherelationshipbetweenthenumberofcubicyardsofmulch,x,andthenumberoftonsofriverrock,y$, Odalys ordered. How much more, in dollars, did a ton of river rock cost Odalys than a cubic yard of mulch?