Given:
Package A
Birthday cards = 3
Thank you notes = 2
Costs = $18
Package B
Birthday cards = 8
Thank you notes = 6
Costs = $50
Required:
x = birthday card cost
y = thank you notes cost
Solution:
Package A:
18 = 3x + 2y
Package B:
50 = 8x + 6y
Second, add the two equations using elimination method.
To find y eliminate x;
[8 (18 = 3x + 2y)] + [-3 (50 = 8x + 6y)]
(144 = 24x + 16y) + [-150 = -24x + (-18y)]
-6 = -2y
Divide both sides with -2.
y = 3 thank you notes cost
Next, let us find x by substituting the value of y.
(18 = 3x + 2y) + (50 = 8x + 6y)
[18 = 3x + 2(3)] + [50 = 8x + 6(3)]
(18 = 3x + 6) + (50 = 8x + 18)
68 = 11x + 24
68 – 24 = 11x
44 = 11x
Divide both sides with 11.
X = 4 birthday card cost
