# Graph: Y=2x-7

#### EORTIZ40

##### New member
I do not know where to start

#### JoJo999

##### New member
Graph Y=2x-7

The easiest way to do this question is to substitute values for x and that will give you y.

Example: If x =1 Y= 2(1)-7 = -5 If x = 2 Y=-3 etc.

#### Semo

##### New member
I do not know where to start
I think my way is actually easier.
-7 is the X-intercept
2X is the slope
Make a point at (-7,0)
The slope is 2/1 and it's positive so you go up 2 and right 1
Make a line #### Scorpy

##### New member
1. Find the domain
2. Find the intercepts by x=0, so y=-7 and vice versa y=0 x=7/2
3. Symmetry (even/odd function) f(-x)
4. Asymptotes
- vertical (find a value that provides non 0 in the numerator and 0 in denominator)
- horizontal (limit as x tend to +/- infinity)
- oblique (by long division, if appropriate)
And be aware that polynomial functions don't have asymptotes!!
5. Increasing/decreasing intervals, max/min and critical points by finding the first derivative
6. Concavity, point of inflection (if occur) by finding the second derivative
7. Sketch the graph by plotting all the points

#### srmichael

##### Full Member
1. Find the domain
2. Find the intercepts by x=0, so y=-7 and vice versa y=0 x=7/2
3. Symmetry (even/odd function) f(-x)
4. Asymptotes
- vertical (find a value that provides non 0 in the numerator and 0 in denominator)
- horizontal (limit as x tend to +/- infinity)
- oblique (by long division, if appropriate)
And be aware that polynomial functions don't have asymptotes!!
5. Increasing/decreasing intervals, max/min and critical points by finding the first derivative
6. Concavity, point of inflection (if occur) by finding the second derivative
7. Sketch the graph by plotting all the points
Scorpy, I understand you wanting to help, but someone that asks how to graph y=2x-7 is not going to understand all the info you mention above.

#### Mrspi

##### Senior Member
I think my way is actually easier.
-7 is the X-intercept
2X is the slope
Make a point at (-7,0)
The slope is 2/1 and it's positive so you go up 2 and right 1
Make a line I understand your desire to help, Semo....but what you have said here is quite simply incorrect, and will probably only serve to confuse the original poster.

Please review the "slope-intercept form" for the equation of a line. The "intercept" in that equation is the y-intercept, not the x-intercept.

#### mjames2

##### New member
I think to understand this you should first understand the basic equation for a straight line:
y = m x + c
(or)
y = m x + b
(c and b are the same thing, it's just a different way of representing the y intercept)
1. m is the gradient or slope; you find m by dividing the rise by the run.
2. x is the x coordinate of the specific point on the line; you can say x or y is a number and use it to find a random point on the line.
3. c is the y intercept; the value of y when x is equal to 0.
Just think of the equation as if it is algebra; you need to figure out the value of y based off what the x is or vice versa. #### Subhotosh Khan

##### Super Moderator
Staff member
I think to understand this you should first understand the basic equation for a straight line:
y = m x + c
(or)
y = m x + b
(c and b are the same thing, it's just a different way of representing the y intercept)
1. m is the gradient or slope; you find m by dividing the rise by the run.
2. x is the x coordinate of the specific point on the line; you can say x or y is a number and use it to find a random point on the line.
3. c is the y intercept; the value of y when x is equal to 0.
Just think of the equation as if it is algebra; you need to figure out the value of y based off what the x is or vice versa. Why are you responding to a 8+ year old thread!!

• jonah2.0

#### jonah2.0

##### Full Member
Beer soaked comment follows.
Why are you responding to a 8+ year old thread!!
May need some ketchup ... beg your pardon; a question mark I mean.

#### Jomo

##### Elite Member
You pick any three x-values, maybe 0, 1 and 2. One by one, you double the x-value and then subtract 7. This will give you the y-value for the corresponding x-value.

For example: if x=9. After doubling it you get 18. after subtracting 7 you get 11. Therefore a point on the line would be (9,11). Do the same for two more x-values and plot the three points. If you made no mistake the points will lie on a straight line. Draw the line.