Question

Solve the following simultaneous equations by the method of equating coefficients.$x-2y=-10;3x-5y=-12$

• A. $x=16,y=18$
• B. $x=32,y=18$
• C. $x=26,y=18$
• D. $x=22,y=18$

Answer 1

Answer: (C)

$x=26,y=18$

$x-2y=-10$ ...(i)

$3x-5y=-12$ ...(ii)

On multiplying (i) by 3, we get

$3x-6y=-30$ ...(iii)

now subtracting (ii) from (iii)

$3x-6y=-30$
$\underset{–}{\underset{-}{3}x\underset{+}{-}5y=\underset{+}{-}12}$
$-y=-18$

$\therefore y=18$

On putting $y=18$ in (ii), we get

$3x-5\left(18\right)=-12$

$3x-90=-12$

$3x=78$

$x=26$

$\therefore x=26,y=18$