# 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 $$7.$$

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