Answer:
See below.
Step-by-step explanation:
(a) Let the cost of the macadamia dough = x and cost of the triple chocolate dough = y.
So we have the following system of equations:
25x + 30y = 221.25 ( Juliens class)
5x + 45y = 191.25 ( Castilejo's class). (Answer).
(b)
Solving:
25x + 30y = 221.25 ......... (1)
5x + 45y = 191.25 ..............(2)
Multiply equation (2) by -5:
-25x - 225y = -956.25 .... (3)
Now add equations (1) and (3):-
-195y = -735
y = $3.77
Substituting in equation (1)
25x + 30(3.77) = 221.25
25x = 221.25 - 113.08 = 108.17
x = $4.33.
Answer The macadamia dough costs $4.33 and the chocolate cost $3.77.
(c) I used the elimination method to solve this because the substitution method would be more awkward - it would involve more calculation and higher numbers.