Astore is having a sale on chocolate chips and walnuts. for pounds of chocolate chips and pounds of walnuts, the total cost is . for 3 pounds of chocolate chips and 2 pounds of walnuts, the total cost is $9 . find the cost for each pound of chocolate chips and each pound of walnuts.

x ----------------------- > the cost of pound of chocolate chips 

y  ---------------------- >  the cost of pound of walnuts

we have that

4x+8y=21-------------------------------------------> 4x+8y=21

2x+3y=9------------> multiply by -2------------> -4x-6y=-18

                                                                    ---------------------

                                                                      0x+2y=3

y=3/2=1.5

then

2x+3y=9--------------> 2x=9-3y----------> x=[9-3y]/2=[9-3*1.5]/2=2.25

x=2.25------------>cost of pound of chocolate chips-------> $2.25

y=1.5--------------> cost of pound of walnuts---------> $1.5

the answer is 

cost of pound of chocolate chips-------> $2.25

cost of pound of walnuts---------> $1.5