+0  
 
0
141
1
avatar+8 

Tomorrow is my exam and I came across this question in my practice paper again. I hate this type of questions a lot. Can you help? The second question is:

Mrs Kumar paid $14 438 for 5 similar laptops and 4 similar DVD players. If 1 laptop and 1 DVD player cost $2960 altogether, what was the cost of each DVD player?

CalculatorPlease9987  May 11, 2017
Sort: 

1+0 Answers

 #1
avatar+18612 
0

Mrs Kumar paid $14 438 for 5 similar laptops and 4 similar DVD players.

If 1 laptop and 1 DVD player cost $2960 altogether,

what was the cost of each DVD player?

 

Let x = laptop
Let y = DVD player

 

\(\begin{array}{|lrcll|} \hline (1) & x+y &=& $2960 \quad & | \quad -y \\ & x &=& 2960 - y \\\\ (2) & 5x+4y &=& $14438 \quad & | \quad x= 2960 - y \\ & 5\cdot (2960 - y) + 4y &=& 14438 \\ & 5\cdot 2960 - 5y + 4y &=& 14438 \\ & 14800 - 5y + 4y &=& 14438 \\ & 14800 - y &=& 14438 \quad & | \quad \cdot (-1) \\ & -14800 + y &=& -14438 \quad & | \quad +14800 \\ & y &=& 14800 - 14438 \\ & \mathbf{y} & \mathbf{=} & \mathbf{$362 } \\\\ & x &=& 2960 - y \quad & | \quad y= 362 \\ & x &=& 2960 - 362 \\ & \mathbf{x} & \mathbf{=} & \mathbf{$2598 } \\ \hline \end{array}\)

 

Each DVD player cost $362

 

laugh

heureka  May 11, 2017
edited by heureka  May 11, 2017
edited by heureka  May 11, 2017

24 Online Users

avatar
avatar
avatar
avatar
avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details