HELP plEASE!!!!!!!!!!!!!!!!!!!!!!!!?

Question

Given two points slope, write the equation of the line in the slope-intercept form.
.
(-1,9) and (2,0)

I still dont get it

Also
(3, -2) and (-3,-6
(4,0) and (6,1)

Answer 1

equation=(y-y1)/(y2-y1)=(x-x1)/(x2-x1)
1.(y-9)/-9=(x+1)/3
3(y-9)=-9(x+1)
y-9=-3(x+1)
y=-3x+6

2.(y+2)/-4=(x-3)/-6
-6(y+2)=-4(x-3)
y+2=2/3x-2
y=2/3x-4

3.(y-0)/1=(x-4)/2
2y=x-4
y=1/2x-2

Answer 2

Go to: http://www.gomath.com/exercises/SlopeEquationYintercept.php

Click on Mini-Lessons for explanation.

For the points given (-1,9) -1 is X1 and 9 is Y1
For the points given (2,0) 2 is X2 and 0 is Y2

So fill in the X1, X2, Y1, & Y2 in the slope equation and calculate the result for m. The result is -3. Then fill in the y-intercept and calculate the result. y in this case is 9, x is -1, and m is -3, so 9 - -3 *-1. The result is 6. Fill in the Equation for m and b.

Equation: y = mx + b
Slope: m = (Y2-Y1) / X2-X1)
y-intercept: b = y - mx

Answer 3

y = mx + b

to find m (the slope), the formula is (y2-y1)/(x2-x1) = 0-9/2-(-1)

-9/3 = -3 so m = -3

find b, the formula is b=y-mx

b = 0-(-3)*2 = 6
or
b = 9- (-3)(-1) = 6

so your equation becomes y = mx + b

y = -3x + 6

tada! :) u can do it for the next to points


try this website it will help explain things and u can check ur answers after putting in the points! :)

Answer 4

gradient = (y2-y1)/(x2-x1), where (x1, y1) and (x2,y2) are 2 points on the line.

thus, using (4,0) and (6,1), gradient = (1-0)/(6-4) = 1/2

the equation of a line is y = mx +c, where m is the gradient and c is the y-intercept.

thus, y= 0.5x+c

since (4,0) is on the line, sub it back into above eqn:
0 = 0.5(4) +c, which will yield c = -2

thus eqn becomes y = 0.5x-2

Answer 5

draw a quadrant graph, mark your points, connect them if you wish and slope equals rise over run. that's all I remember from 25 plus years ago. and I thought I'd never use this crap.

Answer 6

You should ask your teacher to explain it to you again. Math is something better to explain one on one.