If x [ l 1 2 ]+y [ l 2 5 ]= [ l 4 9 ], then - Vidyadip

MCQ

If $x\left[\begin{array}{l}1 \\ 2\end{array}\right]+y\left[\begin{array}{l}2 \\ 5\end{array}\right]=\left[\begin{array}{l}4 \\ 9\end{array}\right]$, then

A
$x=1, y=2$
B
$x=2, y=1$
C
$x=1, y=-1$
D
$x=3, y=2$

✓

Answer

We have, $x\left[\begin{array}{l}1 \\ 2\end{array}\right]+y\left[\begin{array}{l}2 \\ 5\end{array}\right]=\left[\begin{array}{l}4 \\ 9\end{array}\right]$
\[\Rightarrow\left[\begin{array}{c}
x+2 y \\
2 x+5 y
\end{array}\right]=\left[\begin{array}{l}
4 \\
9
\end{array}\right]
\]$\Rightarrow x+2 y=4$ ...(i) and $2 x+5 y=9$ ....(ii)
Solving (i) and (ii), we get $x=2, y=1$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Matrices→Matrices — all question types→Maths STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

If $\text{y}=\text{a}\sin\text{mx}+\text{b}\cos\text{mx},$ then $\frac{\text{d}^2\text{y}}{\text{dx}^2}$ is equal to:

-m²y
m²y
-my
my

$\int {\frac{{dx}}{{{{\cos }^3}x\sqrt {2\sin 2x} }}} $ is equal to

If $\tan (x + y) = 33$ and $x = {\tan ^{ - 1}}3,$ then $y $ will be

$\int_{}^{} {\frac{{dx}}{{1 - \sin x}}} = $

If $y = 2sin^{-1} \sqrt {(1-x)} + sin^{-1} (2\sqrt{x(1-x)})$ for $0 < x < \frac{1}{2}$, then $\frac{dy}{dx}$ equals-

The point at which the maximum value of x + y, subject to the constraints x + 2y ≤ 70, 2x + y ≤ 95, x, y ≥ 0 isobtained, is:

(30, 25)
(20, 35)
(35, 20)
(40, 15)

Differential equation of $y = A{e^{2x}} + B{e^{ - 2x}}$ is (Where $A$ and $B$ are arbitrary constants)

$\int_{\,0}^{\,\pi /2} {\{ x - [\sin x]\} \,dx} $ is equal to

Let $f ( x )=\sum \limits_{ k =1}^{10} kx ^{ k }, x \in R$. If $2 f(2)+f^{\prime}(2)=119(2)^{ n }+1$ then $n$ is equal to $..........$.

If $\text{x}=\text{f}(\text{t})\cos\text{t}-\text{f}(\text{t})\sin\text{t}\ \text{and}\ \text{y}=\text{f}(\text{t})\sin\text{t}+\text{f}(\text{t})\cos\text{t},$ then $\Big(\frac{\text{dx}}{\text{dt}}\Big)^2+\Big(\frac{\text{dy}}{\text{dt}}\Big)^2=$

$\text{f}(\text{t})-\text{f}(\text{t})$
$\{\text{f}(\text{t})-\text{f}(\text{t})\}^2$
$\{\text{f}(\text{t})+\text{f}(\text{t})\}^2$
$\text{None of these}$