Question

draw the graph X + Y - 1 is equal to zero and x minus y + 3 is equal zero in the same graph and find the coordinates of the point where two lines intersect

Answer 1

your answer is (0,2) because
x+y-1=0 then
x+y= -1
so,y+3= -1
then
y=3-1
y=2

Answer 2

X+Y=1        eq. 1

X-Y=-3        eq 2

from eq1

X=1-Y

substituting the value in eq 2

X-Y=-3

=1-Y-Y=-3

=1-2Y=-3

=-2Y=-4

=Y=2

SUBSTITUTING THE VALUE OF Y IN EQ 1

X+Y=1

=X+2=1

=X=-1

SO two lines will intersect at (-1,2)