# Ex.4.2 Q4 Linear Equations in Two Variables Solution - NCERT Maths Class 9

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## Question

Find the value of \(k,\) if \(x = 2, y = 1\) is a solution of the equation \(2x + 3y = k.\)

Video Solution

Linear Equations In Two Variables

Ex 4.2 | Question 4

## Text Solution

**What is known?**

Linear equation \(\begin{align}2x + 3y = k.\end{align}\)

** What is Unknown?**

Value of \(K\).

** Reasoning:**

We can find value of \(k\) by substituting the values of *\(x\) and \(y\)* in the given equation.

**Steps:**

**Given :**

\(2x + 3y = k\) is the Linear Equation ---------------- Equation (\(1\))

- \(x = 2\)
- \(y = 1\)
- \(k =?\)

By substituting the values of \(x\) and \(y\) in Equation (\(1\)),

\[\begin{align}&2x + 3y = k\\&\Rightarrow(2)(2) + 3(1) = k\\&\Rightarrow4 + 3 = k\end{align}\]

Hence, \(k = 7\)

Therefore, the value of \(k\) is \(7.\)

Video Solution

Linear Equations In Two Variables

Ex 4.2 | Question 4