SOLUTION: Write the slope-intercept in form of an equation: (-2,o) and (7,4) It really helps me to understand if I can See each step to solve this problem written out like in a math bo

Algebra ->  Linear-equations -> SOLUTION: Write the slope-intercept in form of an equation: (-2,o) and (7,4) It really helps me to understand if I can See each step to solve this problem written out like in a math bo      Log On


   



Question 172824: Write the slope-intercept in form of an equation:
(-2,o) and (7,4)
It really helps me to understand if I can See each step to solve this problem written out like in a math book. Thank you

Found 2 solutions by nerdybill, jim_thompson5910:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Slope-intercept form:
y = mx + b
where
m is slope
b is y-intercept
.
Given the two points:
(-2,o) and (7,4)
You can determine the slope:
m = (y2-y1)/(x2-x1)
plugging in our values:
m = (4-0)/(7-(-2))
m = (4-0)/(7+2)
m = 4/9
.
Plug in the slope (above) and one of the two points given say, (-2,0) into the slope-intercept form to find 'b':
y = mx + b
0 = (4/9)(-2) + b
0 = -8/9 + b
b = 8/9
.
Now, that we know m and b:
y = mx + b
y = (4/9)x + (8/9) (this is what they're looking for)


Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

First let's find the slope of the line through the points and


m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula.


m=%284-0%29%2F%287--2%29 Plug in y%5B2%5D=4, y%5B1%5D=0, x%5B2%5D=7, and x%5B1%5D=-2


m=%284%29%2F%287--2%29 Subtract 0 from 4 to get 4


m=%284%29%2F%289%29 Subtract -2 from 7 to get 9


So the slope of the line that goes through the points and is m=4%2F9


Now let's use the point slope formula:


y-y%5B1%5D=m%28x-x%5B1%5D%29 Start with the point slope formula


y-0=%284%2F9%29%28x--2%29 Plug in m=4%2F9, x%5B1%5D=-2, and y%5B1%5D=0


y=%284%2F9%29%28x--2%29 Simplify


y=%284%2F9%29%28x%2B2%29 Rewrite x--2 as x%2B2


y=%284%2F9%29x%2B%284%2F9%29%282%29 Distribute


y=%284%2F9%29x%2B8%2F9 Multiply



So the equation that goes through the points and is y=%284%2F9%29x%2B8%2F9