Question

The points (-2, 17) and (3, r) lie on a line with slope -4. Find the missing coordinate r

Answer 1

Answer: r=-3

Explanation:

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

-4=(r-17)/(3-(-2))

-4=(r-17)/5

r-17=-20

r=-3

Answer 2

(3, -3), r= -3.

Explanation:

1. Find the equation of the line.

Using the point and the slope, we are able to find the equation of this line.

Formula:
`y-y_1=m(x-x_1)`, where
`x_1` and
`y_1` are the coordinates of a point the function goes through, and m is the slope of the equation.

Substitute in the formula and calculate.

`y-(17)=(-4)(x-(-2))\\ \\y-17=-4(x+2)\\ \\y-17=(-4)(x)+(-4)(2)\\ \\y-17=-4x-8\\ \\y-17+17=-4x-8+17\\ \\y=-4x+9`

2. Complete the ordered pair.

The irdered pair we're trying to complete has an x with a value of 3. Hence, if we use that value and substitute in the formula we found for the equation, we can find the y value and complete the ordered pair.

`y=-4(3)+9\\ \\y=-12+9\\ \\y=-3`