# Struggling with linear graphs

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#1
I have a question
"On the grid, draw the graph of y = 4x − 1 from x = −2 to x = 4"
I am unsure how to get the y and x value out of these equations, could anyone explain or recommend a video/website to help me?
0
1 week ago
#2
From this equation, and the given x values (x = -2 and x = 4), you will get two coordinates (two y values for each of those x values).

To find the y value for the first x value (x = -2), you need to put the number -2 into the equation where x is. So it becomes:

y = 4(-2) - 1, when you multiply 4 by -2, you get: y = - 8 - 1, which then gives you y = -9. That means the first coordinate is (-2,-9)

To find the y value for the second x value (x = 4), you will need to put the number 4 into the equation where x is. So it becomes:

y = 4(4) - 1, when you multiply 4 by 4, you get: y = 16 - 1, which then gives you y = 15. That means the second cordinate is (4,15)

You then use the two coordinates and plot them on a graph, which will give you two points. Connect the two points with a straight line, and you have your linear graph
0
#3
(Original post by Vauntedmango)
From this equation, and the given x values (x = -2 and x = 4), you will get two coordinates (two y values for each of those x values).

To find the y value for the first x value (x = -2), you need to put the number -2 into the equation where x is. So it becomes:

y = 4(-2) - 1, when you multiply 4 by -2, you get: y = - 8 - 1, which then gives you y = -9. That means the first coordinate is (-2,-9)

To find the y value for the second x value (x = 4), you will need to put the number 4 into the equation where x is. So it becomes:

y = 4(4) - 1, when you multiply 4 by 4, you get: y = 16 - 1, which then gives you y = 15. That means the second cordinate is (4,15)

You then use the two coordinates and plot them on a graph, which will give you two points. Connect the two points with a straight line, and you have your linear graph
Thankyou!! I have one more question if you could answer it please- y=6x + 1 How do I work this out?
0
1 week ago
#4
(Original post by noodlestopshop)
Thankyou!! I have one more question if you could answer it please- y=6x + 1 How do I work this out?
I'm assuming its to be solved with the same x values (x = -2 and x = 4).

Same method. For the first x value (x = -2), the y value can be found by putting -2 where x is:

y = 6(-2) + 1. Multiplying 6 by -2 gives: y = -12 + 1, which gives y = -11. So the first coordinate is (-2, -11)

For the second x value (x = 4), the y value can be found by putting 4 where x is:

y = 6(4) + 1. Multiplying 6 by 4 gives: y= 24 +1, which gives y = 25. So the second coordinate is (4, 25)
0
1 week ago
#5
(Original post by Vauntedmango)
From this equation, and the given x values (x = -2 and x = 4), you will get two coordinates (two y values for each of those x values).

To find the y value for the first x value (x = -2), you need to put the number -2 into the equation where x is. So it becomes:

y = 4(-2) - 1, when you multiply 4 by -2, you get: y = - 8 - 1, which then gives you y = -9. That means the first coordinate is (-2,-9)

To find the y value for the second x value (x = 4), you will need to put the number 4 into the equation where x is. So it becomes:

y = 4(4) - 1, when you multiply 4 by 4, you get: y = 16 - 1, which then gives you y = 15. That means the second cordinate is (4,15)

You then use the two coordinates and plot them on a graph, which will give you two points. Connect the two points with a straight line, and you have your linear graph
Great explanation. Just a heads up that it's best practice to not put the values in and give the final answer yourself. You want to explain that you want to put the values into the equation, but let the person who asked do that and figure it out themselves. (Same with your other post)
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