Answer:
y = -x+7
Explanation:
We need to get x+y=4 in slope intercept from to determine the slope
x+t=4
Subtract x from each side
x-xy = -x+4
y= -x+4
The slope is -1
Parallel lines have the same slope
We have the slope and a point of the new line.
We can use the point slope form
y-y1 = m(x-x1)
y-8 = -1(x--1)
y-8 = -1(x+1)
Distribute the negative sign
y-8 = -x-1
Add 8 to each side
y-8+8 = -x-1+8
y = -x+7