A store is having a sale on jelly beans and trail mix. For 3 pounds of jelly beans and 5 pounds of trail mix, the total cost is
$17 . For 9 pounds of jelly beans and 7 pounds of trail mix, the total cost is $37 . Find the cost for each pound of jelly beans and each pound of trail mix.
Set up your two equations: <span>9x+7y=53 </span> <span>3x+5y=25 </span> <span>X=cost per pound of jelly bean </span> <span>Y=cost per pound of trail mix </span> <span>Multiply the second equation by (-3): </span> <span>-9x-15y=-75 </span> <span>+ 9x+7y=53 <---- copy first equation and add them </span> <span>—————— </span> <span>0x-8y=-22 </span> <span>Then solve for y: </span> <span>Y=2.76 this is your cost per pound of trail mix. </span> <span>Then plug y back in to one of the original equations and solve for x: </span> <span>3x+7(2.75)=25 </span> <span>X=3.75 this is you cost per pound of jelly beans</span>
An Independent variable can change the dependent variable because the independent variable can be changed alone while a dependent variable can also be changed by another variable.
