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3 years ago

A line has a slope of -8 and includes the points (-10, 0) and (-9, z). What is the value of Z?

Mathematics

2 answers:

Evgesh-ka [11]3 years ago

6 0

Answer:

Step-by-step explanation:

Let L be the given line, then, with a slope of -8

L : y = -8x + b

where b is to be determined from the included point A(-10,0).

Substitute point A in L to get

0 = -8 (-10) + b

solve to get

b = -80

therefore

L : y = -8x -80

Now substitute B(-9,z) in L

z = -8(-9) - 80 = -8

Shalnov [3]3 years ago

5 0

Answer:

z = -8

Step-by-step explanation:

Given coordinate points are:

(-10 , 0) = (x1 , y1)

(-9 , z) = (x2 , y2)

slope ( m) = y2-y1/x2-x1

-8 = z - 0/-9 - (-10)

-8 = z/-9 + 10

-8 = z/1

-8*1 = z

-8 = z

therefore the value of z is -8.

You might be interested in

Write the equation of the line that passes through (−3,1) and (2,−1) in slope-intercept form

Alex787 [66]

Answer:

$y=-\frac{2}{5}x-\frac{1}{5}$

Step-by-step explanation:

The equation of a line is y = mx + b

Where:

m is the slope

b is the y-intercept

First, let's find what m is, the slope of the line.

Let's call the first point you gave, (-3,1), point #1, so the x and y numbers given will be called x1 and y1.

Also, let's call the second point you gave, (2,-1), point #2, so the x and y numbers here will be called x2 and y2.

Now, just plug the numbers into the formula for m above, like this:

$m = -\frac{2}{5}$

So, we have the first piece to finding the equation of this line, and we can fill it into y=mx+b like this:

$y=-\frac{2}{5}x + b$

Now, what about b, the y-intercept?

To find b, think about what your (x,y) points mean:

(-3,1). When x of the line is -3, y of the line must be 1.
(2,-1). When x of the line is 2, y of the line must be -1.

Now, look at our line's equation so far: $y=-\frac{2}{5}x + b$ . $b$ is what we want, the - $-\frac{2}{5}$ is already set and x and y are just two 'free variables' sitting there. We can plug anything we want in for x and y here, but we want the equation for the line that specfically passes through the two points (-3,1) and (2,-1).

So, why not plug in for x and y from one of our (x,y) points that we know the line passes through? This will allow us to solve for b for the particular line that passes through the two points you gave!

You can use either (x,y) point you want. The answer will be the same:

(-3,1). y = mx + b or $1=-\frac{2}{5} * -3 + b$ , or solving for b: $b = 1-(-\frac{2}{5})(-3)$ . $b = -\frac{1}{5}$ .
(2,-1). y = mx + b or $-1=-\frac{2}{5} * 2 + b$ , or solving for b: $b = 1-(-\frac{2}{5})(2)$ . $b = -\frac{1}{5}$ .