Q. 2 B3.6( 5 Votes )

# Solve the following pair of linear equations by substitution method:

x + y = 2m

mx — ny = m^{2} + n^{2}

Answer :

Given equations are

x + y = 2m …(i)

mx – ny = m^{2} + n^{2} …(ii)

From eq^{n} (i), x = 2m – y …(iii)

On substituting x = 2m – y in eq^{n} (ii), we get

⇒ m(2m – y) – ny = m^{2} + n^{2}

⇒ 2m^{2} – my – ny = m^{2} + n^{2}

⇒ – y(m + n) = m^{2} – 2m^{2} + n^{2}

⇒ – y(m + n) = – m^{2} + n^{2}

⇒ y = – (n – m) = m – n

Now, on putting **y = m – n** in eq^{n} (iii), we get

⇒ x = 2m – (m – n)

⇒ x = 2m – m + n

⇒ **x = m + n**

Thus, **x = m + n** and **y = m – n** is the required solution.

Rate this question :

How useful is this solution?

We strive to provide quality solutions. Please rate us to serve you better.

Related Videos

Pair of Linear Equations in Two Variables46 mins

Dealing With the Real Life Problems53 mins

Quiz | Real Life Problems Through Linear Equations56 mins

Quiz | Solution of Linear Equations53 mins

Champ Quiz | Consistency and Inconsistency of Solutions36 mins

Emphasizing on Elimination Method48 mins

Consistent and Inconsistent Equations33 mins

Elimination (quicker than quickest)44 mins

Algebraic Methods to Solve Pair of Linear Equation44 mins

Real Life Problems Through Linear Equations41 mins

Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Expertsview all courses

Dedicated counsellor for each student

24X7 Doubt Resolution

Daily Report Card

Detailed Performance Evaluation

RELATED QUESTIONS :