Question

The points (-3,9) and (-1,r) lie on line with slop -2.

Answer 1

The value of r is 5

Explanation:

The question is

Find out the value of r

we know that

The formula to calculate the slope between two points is equal to

`m=(y2-y1)/(x2-x1)`

we have the points

(-3,9) and (-1,r)

substitute

`m=(r-9)/(-1+3)`

`m=(r-9)/(2)`

Remember that

`m=-2`

substitute the value of m

`-2=(r-9)/(2)`

Solve for r

Multiply by 2 both sides

`-4=r-9`

Adds 9 both sides

`-4+9=r-9+9`

`5=r`

Rewrite

`r=5`