Question

Find the value of $x$ and $y$ using substitution method:
$x-y=2$ and $2x-y=9$

• A. $7$ and $7$
• B. $7$ and $5$
• C. $-7$ and $-5$
• D. $5$ and $7$

Answer 1

Answer: (B)

$7$ and $5$

$x-y=2$ ------- $\left(1\right)$
$2x-y=9$ ------ $\left(2\right)$
From equation $\left(1\right)$ :
$y=x-2$
Substitute the value of $y$ in equation $\left(2\right)$:
$2x-y=9$
$2x-x+2=9$
$x=9-2$
$x=7$
Now, Substitute $x=7$ in equation $\left(1\right)$:
$x-y=2$
$7-y=2$
$y=7-2$
$y=5$
Therefore the solution is: $x=7$ and $y=5$