Respuesta :
Answer:
Each birthday card costs $2.2 ⇒ answer c
Step-by-step explanation:
* Lets explain how to solve the problem
- Package A contains 3 birthday cards and 2 thank-you notes
- It costs $9.60
- Package B contains 8 birthday cards and 6 thank-you notes
- It costs $26.60
- x represents the cost of birthday card and y represents the cost of
thank-you note
* Lets change these information to two equations
∵ x represents the cost of each birthday cards
∵ y represents the cost of each thank-you notes
∵ Bag A contains 3 birthday cards and 2 thank-you notes
∵ Bag A costs $9.60
∴ 3x + 2y = 9.60 ⇒ (1)
∵ Bag B contains 8 birthday cards and 6 thank-you notes
∵ Bag B costs $26.60
∴ 8x + 6y = 26.60 ⇒ (2)
* Lets solve this system of equations to find x and y
- Multiply equation (1) by -3 to eliminate y
∵ -3(3x) + -3(2y) = -3(9.60)
∴ -9x - 6y = -28.8 ⇒ (3)
- Add equations (2) and (3)
∴ -x = -2.2
- Multiply both sides by -1
∴ x = 2.2
∵ x represents the cost of each birthday cards
∴ The cost of each birthday card is $2.2
* Each birthday card costs $2.2
Answer: The correct option is
(c) $2.20.
Step-by-step explanation: Given that package A contains 3 birthday cards and 2 thank-you notes and costs $9.60. Package B contains 8 birthday cards and 6 thank-you notes and costs $26.60.
Also, x represents the cost of a birthday card and y represents the cost of a thank-you note.
We are to find the cost of each birthday card.
The system of linear equations representing the given situation is given by
[tex]3x+2y=9.60~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\\\\8x+6y=26.60~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(ii)[/tex]
Multiplying equation (i) by 3, we have
[tex]3(3x+2y)=3\times9.60\\\\\Rightarrow 9x+6y=28.80~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(iii)[/tex]
Subtracting equation (ii) from (iii), we get
[tex](9x+6y)-(8x+6y)=28.80-26.60\\\\\Rightarrow x=2.20.[/tex]
Thus, the cost of each birthday card is $2.20
Option (c) is CORRECT.