What is the equation of the line that is perpendicular to -x + y = 7 and passes through (-1, -1)

Question

anonymous · Answer

to do this, the first thing you need is the slope of $-x+y=7$
do you know it?

anonymous · Answer

oh.. no..

anonymous · Answer

ok then lets go slow so you get all the steps

anonymous · Answer

to find the slope of $-x+y=7$, solve the equation for $y$ in one step by adding $x$ to both sides, giving 
$$y=x+7$$

anonymous · Answer

$$y=x+7$$ looks like 
$$y=mx+b$$ where $m$ is the slope.
you don't actually see a number in front of the $x$, this makes $m=1$ i.e. the slope is $1$

ok so far?

anonymous · Answer

yeah..

anonymous · Answer

then you want the slope of the perpendicular line 
that is the "negative reciprocal" of the slope of this line
the negative reciprocal of $1$ is $-1$ so the slope of the line you are looking for is $-1$

anonymous · Answer

the slope of the line is $-1$ and the point is $ (-1, -1)$ use the "point slope" formula and get 
$$y-(-1)=-1(x-(-1))$$ more succinctly written as 
$$y+1=-1(x+1)$$

anonymous · Answer

but its giving me multiple choice answers and thats not one of them..

anonymous · Answer

probably not
that is just what you get when you write the point slope formula
you can solve this equation for $y$ if that is what you need