Question

Solve the equations using elimination method:
$2x+3y=15$ and $3x+3y=12$

• A. $(-3,-7)$
• B. $(-3,7)$
• C. $(-3,6)$
• D. $(3,-7)$

Answer 1

The correct option is B $(-3,7)$

$2x+3y=15$ ----- (1)
$3x+3y=12$ ----- (2)
(-) (-) (-)
_____________
$-x=3$
$x=-3$
Put the value of $x$ in equation (1), we get
$2x+3y=15$
$2(-3)+3y=15$
$-6+3y=15$
$3y=15+6$
$3y=21$
$y=\frac{21}{3}$
$y=7$
Therefore the solution is $(-3,7)$