Unit 5 day 5

Objective: "Students will be able to write an equation of a line given data points"
When you have a x-y table you find the equation and graph the line.

Quiz

1. Write an equation of a line given these data points. (4,10) (8,50)

2. Write an equation of a line given these data points. (3,-9) (5,-13)

3. Write an equation of a line thats parallel to y=2x and goes through the point (4,4) 

Answer key

1.  y=2.5x + 0

You would do the same as in the answer for question two, with the y2-y1 over x2-x1, and after plugging in the data points into the equation, you should be getting the linear equation of y=2.5x.

2. y=-2x
you have to use the equation y2-y1 over x2-x1. You should get -13 - -9 over 5 - 3. After doing the math, you should have -4 over 2, which is equal to -2, and that would be the slope of the linear equation.

3. y=2x-4
To get the answer, you have to plug the points into the equation. You take y=2x, and plug in (4,4). you would then get 4=2(4), which is equal to 4=8. Then you do 4 minus 8, and get -4, which would be the y intercept.
commented on Ryan's blog today.
Youtube video help to explain: