Please Help!!!!!?

Question

A line passing through (5, –1) and (–5, y) is perpendicular to a line with slope .
Find the value of y.

with slope -5/4

Answer 1

The line is perpendicular to a line with slope -5/4, so its slope must be 4/5.

The equation for a line is:

(y - y1) = m(x - x1)

So, using y1 = -1 and x1 = 5 from the first point, and a slope (m) of 4/5 we get:

y - -1 = 4/5(x - 5)
y + 1 = 4/5x - 4
y = 4/5x - 5

Now, plug in your other values to determine the y value for that second point:

y = 4/5(-5) - 5
y = -4 - 5
y = -9

Answer 2

If the slope of the second line is -5/4, then the slope of
any perpendicular line is 4/5, because the slopes of
perpendicular lines are related by the equation :
m2 = -1 / m1.

The equation to the first line is : y = mx + b.
We know m (= 4/5) and we know a point (x, y) = (5, -1).
Substituting gives : -1 = (4/5)5 + b, so b = -5.

The equation is therefore : y = (4/5)x - 5.

Your second point is (-5, y), so substitute -5 for x.

This gives : y = (4/5)(-5) - 5 = -9.

Answer 3

Slope of line = (y + 1) / (-5 - 5) = - (y + 1) / 10

As the line is perpendicular to the line with slope - 5 /4, its slope is 4 / 5

So, - (y + 1 ) / 10 = 4 / 5

y + 1 = - 8

y = - 9.

Answer 4

There's a number missing here.
It's perpendicular to a line with slope ???.
What's the missing number?