Question

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

Answer 1

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 <==