Let the price of a bag of balloon=x and the price of a roll of crepe paper =y 5x+2y=38 12x+14y=128 These are the equation you get from the question 5x+2y=38 -5x -5x 2y=38-5x divide both side by 2 y=19-5/2x
12x+14y=128 plug in the y 12x+14(19-5/2x)=128 12x+266-35x=128 -23x+266=128 -266 -266 -23x=-138 divide both side by -23 x=6 this will be the price of a bag of balloon
5x+2y=38 plug in x 5(6)+2y=38 30+2y=38 -30 -30 2y=8 divide both side by 2 y=4 this will be the price of a roll of crepe paper
