Question

Lisa and Julia are selling cookie dough for a school fundraiser. Customers can buy packages of sugar cookie dough and packages of chocolate chip cookie dough. Lisa sold 13 packages of sugar cookie dough and 6 packages of chocolate chip cookie dough for a total of $252. Julia sold 8 packages of sugar cookie dough and 12 packages of chocolate chip cookie dough for a total of $288. Find the cost of each of one package of sugar cookie dough and one package of chocolate chip cookie dough.

x = ______________________________ y = _______________________________
Equations:
1.

2.
solution: _______________________

Answer 1

x=12...................Cost of one package of sugar cookie dough =$12

y=16...................Cost of chocolate chip cookie dough=$16

Explanation:

The question is on formation of simultaneous equations

Let Sugar cookie dough to be x

Let chocolate chip cookie dough to be y

Equations

Lisa--------13x + 6y = $252------------------(a)

Julia-------8x + 12 y= $288------------------(b)

Solving the equations

12(13x + 6y = 252)----------------156x +72y=3024

6(8x + 12 y= 288)------------------48x + 72y=1728

Eliminate 72y by subtraction

108x=1296---------------------divide both sides by 108 to remain with x

x=1296/108-------x=12-------------------(c)

substitute (c) in (a) above

13x + 6y = 252

(13×12)+ 6y =252

156+6y=252

6y=252-156

6y=96--------------------divide both sides by 6 to remain with y

y=96/6 =16

Solutions

x=12...................Cost of one package of sugar cookie dough =$12

y=16...................Cost of chocolate chip cookie dough=$16