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

\[y=a+\frac{b}{x}\]where a, bare real numbers, if \[y=1\]when \[x=-1\]and \[y=5\] when \[x=-5,\] then \[a+b\] equals:

A) \[-1\]

B) \[0\]

C) \[11\]

D) \[10\]

Correct Answer: C

Solution :

[c] According to the question,

\[1=a+\frac{b}{-1}\Rightarrow a-b=1\] ...(1)

and \[5=a+\frac{b}{-5}\Rightarrow 25=5a-b\] ...(2)

On solving eqs. (1) and (2), we get the values of o and b as 6 and 1 respectively.

\[\therefore \,\,\,\,\,\,\,\,\,\,\,a+b=11\]