Question

What is the equation of the line passing through (1, 7) and parallel to the line y = –x + 5 in standard form?
Answer
x – y = 8
x + y = 8
x + y = –8
x – y = –8

Answer 1

\[y _{1}-y _{2}=m(x _{1}-x _{2})\]
this is eq. of line

Answer 2

y-7= m(x-1) i.e. filling in 1, and 7 for point.
now to work out m (the slope)

Answer 3

the slope of y=-x+5 is -1 because y=mx+c tells us m=-1

Answer 4

our line is parallel to it so our equation becomes:
y-7 = -1(x-1)
y-7=-x+1
or y= -x + 1+7
=> y= -x +8
now from our choices we see:
y+x=+8
so the answer is y+x=8