Question

If the system of equation $ax+y=3,x+2y=3,3x+4y=7$ is
consistent, then value of $a$ is given by

• A. $2$
• B. $1$
• C. $-1$
• D. $0$

Answer 1

The correct option is A $2$

$\begin{array}{}ax+y=3& \text{(1)}\end{array}$
$\begin{array}{}x+2y=3& \text{(2)}\end{array}$
$\begin{array}{}3x+4y=7& \text{(3)}\end{array}$
Solving equation $\left(2\right)$ and $\left(3\right)$ and substitute the value of $x$ and $y$ in equation
$x=1,y=1$
Now $a\left(1\right)+1=3\Rightarrow a=2$