Question

What is the y intercept for ((3, -1) (-1,5)

Answer 1

`(7)/(2)`

Explanation:

y = mx + b We are looking for the b part. First we need to find the m part.

We find the m (slope) by the change in y over the change in x. We find the change by subtraction.

The y values are -1 and 5 (3,-1) and (-1,5)

The x values are -1 and 3 (3, -1) (-1,5)

`(5-(-1))/(-1-3)` =
`(5+1)/(-4)` =
`(6)/(-4)` =
`(3)/(-2)` simplified

Now, we will take the slope we just found (
`(3)/(-2)`) and use the x and y values from one of the points to find the y intercept. It does not make which point we use. I am going to use (3, -1)

y = mx + b Substitute in the y, m and x to solve for b

-1 =
`((3)/(-2))`(3) + b

-1` =
`(9)/(-2)` + b Add
`(9)/(2)` to both sides of the equation

-1 +
`(9)/(2)` = b

`(-2)/(2)` +
`(9)/(2)` = b

`(7)/(2)` = b

Helping in the name of Jesus.