Question

find an equation of the line containing the given pair of points

(-2,-9) (-6,-7)

Answer 1

y=(1/2)x-4

Answer 2

okay, i am not good at math, could you please tell me how you got that answer :D

Answer 3

A line is linear. y=mx+b

If a line passes through a certain point, that line's equation has to be true at that point; it has to be true for those specific x and y values. You can simply substitute the x and y values into the equation of your line.

(-2,-9) means x = -2 and y= -9

y=mx+b
-9= -2m+b

Now substitute in the x and y values from your other point into the equation y=mx+b, to get a second equation with actual numbers in it.

y=mx+b

x= -6
y = -7

-7= -6m+b

so now you have two equations with actual numbers in them...

-9= -2m+b
and
-7= -6m+b

now, you want to figure out what m and b are. There are multiple ways to do this.

One way is to solve one equation for either m or b, like this:

-9= -2m+b
-9+2m= b

Then, substitute what b equals (shown above) into the other equation:

-7= -6m+b

b = (-9+2m)

-7= -6m+(-9+2m)

-7= -4m-9
2 = -4m
2/(-4) = m
m = -1/2

once you've found the value r m it's pretty simple to find out what b is, or vis versa. Just take either of your two equations,

-9= -2m+b
OR
-7= -6m+b

and replace m with "-1/2"

-9= -2(-1/2)+b
OR
-7= -6(-1/2)+b

and solve either one of them for b.

y= mx+b

once you've found m and b, you can write your line's equation:

y= (-1/2)x-10