Question

Tentukan himpunan x-y=2 x+y=1

Answer 1

X-y=2  ................1
x+y=1    .........2

now by adding 1 and 2 we get,
x-y+x+y=2+1
=> 2x=3
=>x=3/2=1.5
now y=1-x=1-1.5=-0.5