Question 163215
Line #1: x+y=1 or y=-x+1 this line has a slope=-1

y=2x-3 this line has a slope=2
No matter what line you have through (2,3) it won't be parallel to both these lines because they are not parallel.

However is you want a line that is parallel to each line then:
y=-x+1 (red line)
3=-(2)+b
3=-2+b
b=3=2
b=5 thus the parallel line is:
y=-x+5 (green line).
{{{ graph( 300, 200, -6, 5, -10, 10, -x +1, -x +5) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -x +1 and -x +5). 
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y=2x-3 (red line)
3=2*2+b
3=4+b
b=3-4
b=-1 
y=2x-1 (green line)
{{{ graph( 300, 200, -6, 5, -10, 10, 2x +3, 2x -1) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions 2x +3 and 2x -1).