Question

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

-x + y = 2

-x – y = 2

x – y = 2

-x – y = 0

x + y = 0

Answer 1

y = x + 7
m1 = 1
m1 × m2 = - 1
1 × m2 = - 1
m2 = - 1

- 1 = - 1(-1) + c
- 1 = 1 + c
c = - 2
y = - x - 2
x + y = - 2
- x - y = 2

the answer is the 2nd one