Question

If x = 2, y = 1 is a solution of the equation 2x + 3y = k, then the value of k is: a. 3 b. 4 c. 5 d. 7 ​

Answer 1

put the value for x and y in equation

2x + 3y = k

2(2) + 3(1) = k

4 + 3 = k

5 = k

option C. 5 is correct

Answer 2

Given,

Equation, $\[2x + 3y = k\]$

Given solution, $\[x = 2,y = 1\]$

Solution,

Given equation is $\[2x + 3y = k\]$

Put the given solution in equation,

$\[\begin{array}{l}2x + 3y = k\\ \Rightarrow 2 \times 2 + 3 \times 1 = k\\ \Rightarrow k = 7\end{array}\]$

Hence the value of k is 7.

The correct option is (d), i.e. 7