Question

Solve graphically the pair of equations $x+3y=6$, and $3x-5y=18$. Hence, find the value of $K$ if $7x+3y=K$

• A. $x=-3,y=1,K=13$
• B. $x=-8,y=5,K=8$
• C. $x=1,y=2,K=29$
• D. $x=6,y=0,K=42$

Answer 1

The correct option is D $x=6,y=0,K=42$

From the graph the point of intersection is $(x,y)=(6,0)$.

Substituting $(x,y)=(6,0)$ in $7x+3y=K$, we get

$7\times 6+3\times 0=K$

i.e $K=42$

Ans- Option D.