Question

What is the equation of the line that passes through the points (-1,-1) and (5, 3)? (Write it in slope intercept form: y = mx +b)

Answer 1

y = mx+b
Where:
m is the slope, and
b is the y-intercept...

Answer 2

let's find what m is, the slope of the line...

Answer 3

For lines like these, the slope is always defined as "the change in y over the change in x" or, in equation form: So we use the slope intercept formula to solve...

Answer 4

(y2−y1)(x2−x1)

Answer 5

plug in the numbers into the formula.
m=3- (-1)\5- (-1) which would be 3+1/5+1= 4/6

Answer 6

=2/3 simplified.

Answer 7

So, we have the first piece to finding the equation of this line, and we can fill it into y=mx+b like this:

Answer 8

y=2/3x+b

Answer 9

To find b, think about what your (x,y) points mean:

(-1,-1). When x of the line is -1, y of the line must be -1.
(5,3). When x of the line is 5, y of the line must be 3.

Answer 10

You can use either (x,y) point you want..the answer will be the same:

(-1,-1). y=mx+b or -1=2/3 × -1+b, or solving for b: b=-1-(2/3)(-1). b=-1/3.

Answer 11

(5,3). y=mx+b or 3=2/3 × 5+b, or solving for b: b=3-(2/3)(5). b=-1/3.

Answer 12

The equation of the line that passes through the points

(-1,-1) and (5,3)

is

y=2/3x-1/3