428,581 views
23 votes
23 votes
3

can find missing coordinates of given points
All of the points in the picture are on the
same line
slope is.
(5, 13)
(C, 10)
(2,4)
х
a. Find the slope of the line. Show your
work
What is the value of C? Describe or show
you got your answer.

User Dfreedm
by
3.2k points

1 Answer

25 votes
25 votes

Answer:

OK, the answer is x = 5, hope it helps

Explanation:

Usually, we use the slope formula to find the slope of a line when we know two points on the line. But if we already know the slope of a line, we can use the slope formula to find a missing coordinate of a point on the line.

Here's the slope formula we'll be using:

Example

Find x if the line through the points (6, x) and (1, -5) has a slope of 2.

Since the slope of the line is 2, we'll replace the m in our slope equation with 2. The two points will give us the numbers and variable that will replace the subscripted variables in the slope equation.

Be careful here! Did you notice that the x in the first point is really the y-coordinate of that point? Now we'll use the slope formula to find the value of x, the missing y-coordinate.

-10 = -5 - x

-5 = -x

-1(-5) = -1(-x)

5 = x

x = 5

OK, the answer is x = 5, but what does the answer mean? It means that if we substitute 5 for the missing coordinate in the first point, the slope of the line between the two points will be equal to 2. If you want to check this answer, just use the slope formula to find the slope of the line between (6,5) and (1,-5). If the slope of this line is 2, you know that your answer of x=5 is correct.

User Basiam
by
2.9k points