1. If they say, Slope -4, x-intercept 7,
does this mean that y=-4x+7?
The equation "y = -4x + 7" does represent the straight line with slope m = -4, but it has a y-intercept
of 7, not an x-intercept of 7.
. . . . .Straight-Line Equations
. . . . .Graphing with Slope and y-Intercept
. . . . .Slope of a Straight Line
. . . . .Intercepts
2. Slope 3, y-intercept 8, does this mean y=3x+8?
The equation "y = 3x + 8" does have a slope of m = 3 and a y-intercept at y = 8. If the question (not included within the post) was "state the equation with the following properties", then your equation is correct.
3. Passes through the points (-1,5) and (2,-1)
would it be possible for me to state y=3x-6?
How did you arrive at this equation? Please show all of your steps.
4. Slope 2/3 and passes through the point (5, 7)
does this mean y=2/3x +7?
How did you arrive at this equation? (For instance, since the line is clearly not horizontal, and since the line clearly passes through y = 7 at x = 5, not at x = 0, how did you arrive at a y-intercept of 7?) Please show all of your steps.
5. Has x-intercept 3 and y-intercept -5
does this mean y=3x-5?
Since the points (3, 0) and (0, -5) do not result in a slope of m = 3, how did you arrive at your equation? Please show all of your steps.
6. Slope 0.1, passes through (-0.1, 0.02)
does this mean y=0.1x+0.02?
I have the same question here as for (4) above...?
7.Function f has f(0.3)=0.8 and f(0.8)=-0.4
I have no idea what this means -
Your class certainly does seem to skip a lot...
To learn about functions and function notation, try here:
. . . . .Functions
. . . . .Function Notation
Once you have learned what their notation means, you'll see that they've given you two points, (x, y) = (0.3, 0.8) and (x, y) = (0.8, -0.4). Then you can proceed as usual.
8. Function f has f(-2)=7 and f(3)=-3
what does this mean? do I have to input -2 as a value of x? and -3 as a value of x? how do I get my y values and how do I create a formula for this linear function.
Study the lessons in the links for exercise (7) to learn the necessary background material.