Question

1/x + 1/y =1
1/x-2/y=-1

Answer 1

a)
$\frac{1}{x} + \frac{1}{x} = 1 \\ x = 0 \\ \frac{2}{x} = 1 \\ x = 2$
b)
$\frac{1}{x} - \frac{2}{x} = - 1 \\ x = 0 \\ \frac{3}{x} = - 1 \\ - x = 3 \\ x = - 3$