Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Algebra

Question:

If $3\begin{bmatrix} x& 3\\2 & 1\end{bmatrix} + 4\begin{bmatrix}1 & 2\\5 & y\end{bmatrix} = \begin{bmatrix}10 & 17\\26 & 11\end{bmatrix}$

then the value of (3x+ 2y) is :

Options:

10

13

2

15

Correct Answer:

10

Explanation:

The correct answer is Option (1) → 10

$3\begin{bmatrix} x& 3\\2 & 1\end{bmatrix} + 4\begin{bmatrix}1 & 2\\5 & y\end{bmatrix} = \begin{bmatrix}10 & 17\\26 & 11\end{bmatrix}$

$⇒\begin{bmatrix}3x+4&9+8\\6+20&3+4y\end{bmatrix}= \begin{bmatrix}10 & 17\\26 & 11\end{bmatrix}$

$⇒\begin{bmatrix}3x+4&17\\26&3+4y\end{bmatrix}= \begin{bmatrix}10 & 17\\26 & 11\end{bmatrix}$

$⇒3x+4=10⇒x=2$

$⇒4y+3=11⇒x=2$

$∴3x+2y=3×2+2×2=10$