Question

Find the solution of the pair of equations $\frac{x}{10}+\frac{y}{5}-1=0$ and $\frac{x}{8}-\frac{y}{6}=15$.

Answer 1

Give equations,

$\frac{x}{10}+\frac{y}{5}=+1,\frac{x}{8}+\frac{y}{6}=15$

$5x+1y=50,3x-4y=15\times 2\times 3\times 4$

$x+2y=10⟶\left(1\right),3x-4y=360⟶\left(2\right)$

$2x+4y=20$

Adding equation $\left(1\right)$ and $\left(2\right)$

$5x=380$

$x=76,y=-33$

$(x,y)=(76,-33)$