Question

Solve the following simultaneous equations by the method of equating coefficients.$4x+y=34;x+4y=16$

• A. $x=8,y=2$
• B. $x=4,y=2$
• C. $x=9,y=2$
• D. $x=2,y=2$

Answer 1

Answer: (A)

$x=8,y=2$

$4x+y=34$ ...(i)

$x+4y=16$ ...(ii)

On multiplying (ii) by 4, we get

$4x+16y=64$ ...(iii)

now subtracting (i) from (iii)

$4x+16y=64$
$\underset{–}{\underset{-}{4}x\underset{-}{+}y=\underset{-}{3}4}$
$15y=30$

$\therefore y=2$

On putting $y=2$ in (i), we get

$4x+2=34$

$x=8$

$\therefore x=8,y=2$