Question

The solution of the two simultaneous equations $2x+y=8$ and $3y=4+4x$ is

• A. $x=4,y=1$
• B. $x=1,y=4$
• C. $x=2,y=4$
• D. $x=3,y=-4$

Answer 1

The correct option is C $x=2,y=4$

The given equations are

$2x+y=8$

$2x+y-8=\mathrm{0.........}\left(i\right)$ and

$3y=4+4x4x-3y+4=\mathrm{0..........}\left(ii\right)$

Applying cross multiplication method,

$\frac{x}{1\times \left(4\right)-(-8)(-3)}=\frac{-y}{2\times \left(4\right)-(-8)\times 4}=\frac{1}{2\times (-3)-1\times 4}⟹\frac{x}{-20}=\frac{-y}{40}=\frac{1}{-10}⟹x=2,y=4.\therefore (x,y)=(2,4)$

Hence, the answer is $x=2,y=4$.