10th Class Mathematics Pair of Linear Equations in Two Variables Question Bank MCQs - Pair of Linear Equations in Two Variables

If \[x=a,\] \[y=b\] is the solution of the pair of equations \[\text{x}-\text{y}=\text{2}\]and \[\text{x}+\text{y}=\text{4},\]then the value of a and b are:

A) 3, 1

B) 1, 3

C) -1, 3

D) -3, 1

Correct Answer: A

Solution :

[a] Given, \[x-y=2\]and \[x+y=4\]

\[x=a,\,\,y=b\]is the solution of above equations

\[\therefore \,\,\,\,\,\,\,\,\,\,\,\,\,a-b=2\] and \[a+b=4\]

Adding both equations,

\[2a=6\,\,\,\,\,\,\Rightarrow \,\,\,\,\,\,\,a=3\]

and \[b=4-3=1\]