Find the equation of the line that is perpendicular to x - y = - 5 and passes through (4, 7).

y = - x - 9

y = x - 15

y = - x + 11

y = x + 7

X - y = - 5

-y = - x - 5

y = x + 5 ... slope here is 1. A perpendicular line will have a negative reciprocal slope. All that means is flip ur slope and change the sign. So our perpendicular line will have a slope of - 1.

y = mx + b

slope (m) = - 1

(4,7) ... x = 4 and y = 7

now we sub and find b, the y int

7 = - 1 (4) + b

7 = - 4 + b

7 + 4 = b

11 = b

so ur perpendicular equation is : y = - x + 11 <==