Answer:
x = 0
Step-by-step explanation:
We can find the missing value by solving for the other points (graphically or algebraically). We would first find the line of Points A and B in order to find the parallel line that would help us find the coordinate point with the x-value.
1) Graph points A, B, and C.
2) Calculate the slope of points A and B by using the slope formula:
y2 - y1/x2 - x1.
-1 - 4/-3 - 1....The slope is 5/4.
3) Write 4 = 5/4(x) + b
**We get 4 from the point A (1, 4)
Plug 1 into x and solve for 4 in order to get your y-intercept.
4 = 5/4(1) + b
4 = 5/4 +b
**If 1 = 4/4, then 4 = 16/4.
16/4 = 5/4 + b
11/4 = b
2.75 = b
4) So our y-intercept is 2.75. We now have an equation of y = 5/4x + 2.75 (graph it along with points A and B to see that it intersect both points.
5) Now we will use that line to find a line parallel to it. We know that if two lines have the same slope then they are parallel, so for the equation of the parallel line, we write: y = 5/4x + b so far.
6) We will find the y-intercept and use that to find the x-value of point D.
First we plug in the x and y values of point C to find the y-intercept
y = 5/4x + b --> 3 = 5/4(8) + b --> 3 = 40/4 + b --> 3 = 10 + b --> -7 = b
7) Now we have the equation of the line that is parallel to line AB: y = 5/4x -7
To find the missing value of x, plug the y-value of point D into the equation and solve for x.
--> -7 = 5/4x -7
--> x = 0
**You can double check this by graphing each point and both equations for the lines.
