math project i need help!!!

[kkelly]

i have this math problem where i have the coordinate (51,2.55) and (91,3.40) how do i find.... this is what i have so far
1)the slope of the line that passes through the two points
2) find the y intercept of the line that passes through the two points
3) find the x intercept of the line that passes through the two points

 

[mmm4444bot]

… how do i find

1) the slope of the line that passes through the two points



Use the formula for calculating slope from the coordinates of two points on a line.

Let (51, 2.55) be the coordinates for point 1.

Let (91, 3.40) be the coordinates for point 2.

Then, you have the following.

x[sub:zo4d0kbo]1[/sub:zo4d0kbo] = 51

y[sub:zo4d0kbo]1[/sub:zo4d0kbo] = 2.55

x[sub:zo4d0kbo]2[/sub:zo4d0kbo] = 91

y[sub:zo4d0kbo]2[/sub:zo4d0kbo] = 3.40



2) find the y intercept of the line that passes through the two points



Take the slope that you find from part (1), as well as the given coordinates for point 1, and put them into the Point-Slope formula to write an equation for the line.

Then, set x = 0 and solve for y.

(The x-coordinate for points on the y-axis is always zero. Therefore, any y-intercept point has zero for its x-coordinate.)



3) find the x intercept of the line that passes through the two points



Start with the same Point-Slope equation from above.

This time, set y = 0 and solve for x.

(The y-coordinate for points on the x-axis is always zero. Therefore, any x-intercept point has zero for its y-coordinate.)

If you cannot find the Slope and Point-Slope formulas in your textbook, or you do not understand my instructions, then please let me know.

If you need more help finishing these three exercises, then please show whatever work you've been able to do so far.

 

[kkelly]

Re: math project i need help!!! mmm4444bot

ok so for my y intercept this is what i got....
y=mx+b
y=.85/40(0)+1.47
Y= 1.47???

and for my x intercept this is what i got......
0=.85/40X + 1.47
=1.49????
* really confused need help plzzz!!!!!*

 

[mmm4444bot]

y=.85/40(0)+1.47

Y= 1.47???

YES, but see my comments, below.


0=.85/40X + 1.47

=1.49????

Nope. I asked you to show your work. Where is it?

You wrote the Slope-Intercept form of the equation as:

y = (0.85/40)x + 1.47

This is okay, if you are allowed to round-off the y-intercept to two decimal places. (Personally, I would not write the slope as a fraction. Keep reading.)

We could do better for finding the x-intercept by not rounding any values in our equation.

Go ahead and do the division on the fraction that you wrote for the slope (do not round-off), and do not round the y-intercept to 1.47.

y = 0.02125x + 1.46625

Note that 1.46625 is the exact y-intercept.

Now set y = 0, and solve for the x-intercept.

0.02125x + 1.46625 = 0

Please try to finish. If you would like any more help, then show your work.