Question

Solve the equation using elimination method:
$-x+2y=5$ and $2x+2y=2$

• A. $(1,-2)$
• B. $(-1,2)$
• C. $(1,2)$
• D. $(-1,-2)$

Answer 1

Answer: (B)

$(-1,2)$

$-x+2y=5$ .....(1)
$2x+2y=2$ .....(2)
Multiply equation (2) by $4$ and then subtract the equation (3) and (4)
$-2x+4y=10$ ....(3)
$2x+2y=2$ .....(4)
_____________
$6y=12$
$\Rightarrow y=\frac{12}{6}=2$
Put the value of $x$ in equation (1), we get
$-x+2\left(2\right)=5$
$\Rightarrow -x+4=5$
$\Rightarrow x=4-5$
$\Rightarrow x=-1$
Therefore the solution is $(-1,2)$.