Question

Find the value of two numbers (x.y) if their sum is 12 and their difference is 4.

• A. (6,6)
• B. (5,7)
• C. (8,4)
• D. (10,2)

Answer 1

The correct option is C (8,4)

Let the two numbers be x and y. From the above information we can formulate the following equations :
We can use elimination method by adding the two equations
$x+\text{/}y=12\dots \dots \left(i\right)and\underset{–}{x-\text{/}y=4\dots \dots \left(ii\right)}2x=16\Rightarrow x=8$
$\Rightarrow y=8-4$
$\Rightarrow y=4$
The correct answer is C