The correct option is C x+y=7; 2x−y=8
Pair of equations is said to be consistent if they have at least one solution i.e., one or infinite solutions.
The pair of equations mentioned in options A, B and D has no solution as they are parallel lines. Pair of equations mentioned in C are:
x+y=7 ....(i)
2x−y=8 ....(ii)
Here, a1=1,b1=1,c1=7
a2=2,b2=−1,c2=8
⇒ 12≠1−1
∴ The pair of linear equations given in option C, is consistent and has a unique solution.