From 1
X-y=5
Or x= 5+y
Putting value of x(ie - 5+ y) in eqn. 2
5+2y =7
Or y=(7-5)/2
Solve for y and put the value of y in equation 1
x-y=5
x+y=7
2 answers
just add them:
2x = 12
x = 6
Now subtract them
2y = 2
y = 1
done
2x = 12
x = 6
Now subtract them
2y = 2
y = 1
done