More Random Math Questions?

Question

What is the slope of the line containing the points (-1,4) and (3,2)?


Choose the best description for graphing the point (3,-4).


Put the following equation in slope intercept form 2x - 5y = 10.


What is the slope of the line with equation y = (1/2)x -3?


What is the y intercept of the equation y= (2/3)x -6?


What kind of line is created when you graph the equation x=2?

Answer 1

slope = m = change of y's / change of x's

m = (4-2) / (-1-3)
m = (2) / (-4)
m = -1/2

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When graphing (3, -4) you need to know that (x, y).
Start at (0, 0). So go right 3 spots on the x-axis, and down -4 spots on the y-axis. Make your point there.

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"slope intercept form" - y = mx + b
So isolate the y on one side of the equal sign.
2x - 5y = 10
-5y = -2x + 10
y = (2/5)x - 2

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slope is the m of y = mx + b

y = (1/2)x -3
m = (1/2)

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y-intercept is the b of y = mx + b, where x = 0

y= (2/3)x -6
b = -6
OR written as (0, -6)

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x=2

Go two places to the right on the x-axis and draw a line through it.

Vertical line with undefined slope.


PS You should try these yourself on paper just so you can actually do them on your next exam :)

Answer 2

1. What is the slope of the line containing the points (-1,4) and (3,2)?
m= y' - y / x' - x = -2 / 4 = -1 / 2

2. Choose the best description for graphing the point (3,-4).
i(1,0) & j(0,1) -----> A = 3i - 4j

4. What is the slope of the line with equation y = (1/2)x -3?
m= 1/2

5. What is the y intercept of the equation y= (2/3)x -6?
x=0 -----> y= -6

6. What kind of line is created when you graph the equation x=2?
straight line in x=2, which is parallel to Y - axis.

Answer 3

(2-4)/(3-(-1)) = -2/4 = -1/2

From the origin at (0,0) move 3 units to the right, then move
straight down 4 units. You will now be at the point (3,-4).

2x-5y = 10
-5y = -2x +10
y = 2x/5 - 2 [slope = 2/5, y-intercept = -2

1/2 [slope is number multiplying x]

y-intercept is -6 or (0,-6)

A vertical line that passes through the point (2,0) and is parallel to the y-axis. Every point on this line has the value of x = 2.

Answer 4

And "randomly" reminiscent of some homework assignment questions, I bet.

The best way to plot the point (3,-4)? Draw a Cartesian plane with coordinates. From (0,0), move to the right three units and move down 4 units. Plot the point there.

The slope of a line is "rise over run", which means the change in y over the change in x. If you have two points whose coordinates are (x1,y1) and (x2,y2), then the slope of the line passing through those two points is (y2 - y1) / (x2 - x1).

Slope-intercept form for a line means in the form of y=mx+b, where m and b are constants. When you do this, "m" is the slope and "b" is the y-intercept. This should answer 3 of the questions.

x=2 refers to the line where x=2, regardless of what y is. This means you have a vertical line that passes through (2,0).