Graphing, slope & integers. Please help.

[Guest]

I need help with graphing. If anyone can please help me with the below problems, I'd really be grateful. I have tried this on my own and I am not getting anywhere. Please help me. Thank you!!?

2. Given the line with the equation y= -2, Find three ordered pairs to satisfy the equation. Find the slope of the line. Graph the line.

3. Given the line with equation x =3, Find 3 ordered pairs that satisfy the equation. Find slope of line. Graph the line.

4. Given the line with equation 2x + 5y =10
write equation in slope-intercept form. state slope of the line. state y-intercept of line as ordered pair. Use slope-intercept form to graph line.

5. Find slope of line through points (-3, 7) and (2, -5)

6. Write in point slope form, y - y^1 = m (x - x^1), equation of line through the two points given in above question.

7. Convert equation that wrote in above question to slope intercept form, y = mx + b

8. convert equation in #6 to standard form, Ax + By = C, A, B, C are integers and A > 0

9. Given line with equation 3x-y=5, write equation in point-slope form of line perpendicular to given line through point )3, -2)

10. The manager at a local Best Buy store kept track of daily sales of the iPhone 6 when it was first introduced. He noticed that sales were very high at first, but showed a steady decrease. For example, on day 5 after the phones first went on sale, the store sold 238 iPhone 6’s, but on day 10 after the phones first went on sale, the store sold only 153 iPhone 6’s. Assume that the relationship between number of days since the phone became available and number sold is linear and, let x = the number of days since the phone was released and y = number of phones sold at this Best Buy store.

a) Write two ordered pairs to represent the sales on the days described.


b) Find the slope of the line through those ordered pairs.


c) Write an equation in point-slope form of the line.

d) Convert the equation to slope-intercept form.

e) Explain what the slope and the y-intercept mean in the context of this problem.

[Guest]

You would need to get a book on basic algebra and solving equations by graphical means.
You will not learn the subject here by isolated examples of problems without having a good idea of the concepts used.
There are also numerous sites on the internet for help....it is just a matter or doing a search for them

[Math Tutor]

Take a look at these formulas:

https://www.math10.com/en/geometry/anal ... metry.html

[HallsofIvy]

Perhaps you need to understand what an "equation" means. In the very problem (#2- were you able to do the first problem?) you are given the equation "y= -2" and are asked to find 3 (x, y) points and then draw the line through them. Pick some random value for x- say, x= 0. What is y? Well, y= -2 because that is what the equation says! One point is (0, -2). Do you know where that is on a graph? Choose another value for x, say x= 3. What is y? y= -2! So (3, -2) is on the graph. Choose another value for x, say x= -5 (all these values of x are completely arbitrary). Again, y= -2. So (-5, -2) is on the graph. To find the slope of a line, subtract the y value of "first" point from the y value of the "second". Subtract the x value of the "first" point from the x value of the second (it doesn't matter which point you call "first" and which "second" as long as you do the y and x subtractions in the same order). Divide the y difference by the x difference. Here the "y differences" are all -2- (-2)= -2+ 2= 0 and 0 divided by any number is what?
Draw the line that runs through those three points.

Geometrically, a line is determined by two points. The third point requested here can serve as a check.

The next problem has equation "x= 3". Here, you can't choose x arbitrarily because the equation tells you x always has the value "3". So choose y arbitrarily. Where are the points (3, -5), (3, 0), and (3, 1)? To find the slope, again subtract y values and x values of two points. Here the difference in two x-values is 3- 3= 0. But you can't divide by 0! What does that tell you about the slope?


Problem #4 has equation "2x+ 5y= 10". Now you are free to choose either x or y arbitrarily. However, some choices might be easier than others. For example if I choose x= 3, the equation becomes 6+ 5y= 10. Then, subtracting 6 from both sides, 5y= 10- 6= 4. Then dividing both sides by 5, y= 4/5. That's a perfectly valid answer. It tells us that the point (3, 4/5) is on the graph. But some people, myself included, just don't like fractions. Instead you should quickly see that the two coeficients, 2 and 5, both divide 10 evenly. If we take x= 0, the equation becomes 5y= 10 so y= 10/5= 2. (0, 2) is a point on the graph. And if we take y= 0, the equation becomes 2x= 10 so x= 10/2= 5. (5, 0) is a point on the graph. (They are called the "x and y intercepts" because they are the graph passes through or "intecepts" the x and y axes.)

A tip: In future do not post more than two or three problems at a time. Also, for each problem show some attempt to do the problem yourself. Otherwise it looks like you are just trying to get people to do your homework for you.