I need some help please! ^_^

A) Identify the lines that are perpendicular:
y = -2; y = 1/5x + 3; x = -2; y +3 = -5(x + 2)

B) Write an equation in slope-intercept form for the line parallel to y = 5x - 2 that passes through the point (8, -2).

Respuesta :

perpendicular lines will have negative reciprocal slopes. What that means is if u have a slope of 1/2, to find the negative reciprocal, flip the slope and change the sign.......flip 2/1, change the sign -2/1 or just -2. So the negative reciprocal for the slope of 1/2 is -2. 

A. y = 1/5x + 3.....slope here is 1/5, so for a perpendicular line, u r gonna need an equation with the slope of -5.....and that would be : y + 3 = -5(x + 2).

B. Parallel lines will have the same slope. y = 5x - 2...the slope here is 5...so a parallel line will have a slope of 5.

y = mx + b
slope(m) = 5
(8,-2)...x = 8 and y = -2
now we sub, we r looking for b, the y intercept
-2 = 5(8) + b
-2 = 40 + b
-2 - 40 = b
-42 = b

so ur parallel equation is : y = 5x -42