SOLUTION: If this could be answered ASAP, that would be GREAT! Thanks! 1.Referring to the figure below, write an equation of the line shown in the graph. Use the slope and y-intercep

Algebra ->  Linear-equations -> SOLUTION: If this could be answered ASAP, that would be GREAT! Thanks! 1.Referring to the figure below, write an equation of the line shown in the graph. Use the slope and y-intercep      Log On


   

Question 1048012: If this could be answered ASAP, that would be GREAT! Thanks!
1.Referring to the figure below, write an equation of the line shown in the
graph. Use the slope and y-intercept format: y = mx + b
http://www.ppstest2.com/images2/AL5003.jpg

2. Referring to the figure below, write an equation of the line shown in the
graph. Use the slope and y-intercept format: y = mx + b
http://www.ppstest2.com/images2/AL5004.jpg
Thank you for Helping!
Found 2 solutions by josgarithmetic, addingup:
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
These are the same problem, presented as two different examples.

The slope, m, is the ratio of vertical change to horizontal change as you move on the line from left to right. The y-intercept, b, is the coordinate on the y-intercept for when x is 0; where the line crosses or intersects the y-axis.

Notice that in neither example is the y-intercept easily read clearly. Handle this difficulty using some other easily read point on the line(s).

Your example #1:
Slope obviously is 2%2F3, but y-intercept difficult to read. Looking for ANY other identifyable, readable point, one choice is marked and labeled for you; being (4,5).
-
y=mx%2Bb
mx%2Bb=y
b=y-mx
Substitute coordinates of the "given" point.
b=5-%282%2F3%294
b=5-8%2F3
b=15%2F3-8%2F3
b=7%2F3 or b=2%261%2F3;
-
Equation for the line is highlight%28y=%282%2F3%29x%2B2%261%2F3%29.


You can do your example #2 on your own.

Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
y = how far up, in your graph y = 5
x = how far along, in your graph x = 4
m = slope of the line, calculated like this: m = (change in y)/(change in x)
b = the y intercept
See picture below.
Let's write the equation of your line:
m = Δy/Δx
m = 2/3
b = we don't know, we have to figure it out.
Back to the formula:
y = mx+b
What do we know? We know m, the graph shows us that it's 2/3
We also know y and x, the graph tells us that x = 4 and y = 5
Lets re-write the formula with what we know:
5 = (2/3)4+b Now we simply apply algebra:
5 = 8/3+b
5*3/8 = b
15/8 = b
b = 15/8 = 1 7/8
>>>>>>>>>>>>>>>>
Check:
y = mx+b
5 = (2/3)4+15/8
5 = 8/3+15/8 cross multiply times denominators to find a common denominator
5 = 64/24+45/24
5 = 5 (I get 4.542 due to rounding of numbers)
The process is correct, you may want to check out my math and also make sure I used the right numbers, I mean the numbers off of your graph. Let me know if you have questions.
:
John