First unit of geometry class hw help?

Question

Points R (-1, -5) and S (3,3) lie on the graph at y=2x-3

see which points are collier( I think ) with R &S

point T (0, -3)

U (-0.5, -4)

V (2, -1)

tell which ones are and arent collinear and show ur work.

Plz help, I have no idea what to do!!!!!

Answer 1

You meant collinear maybe?

You just have to substitute the values from the coordinates into the equation.

First, substitute the values you have for Point R (-1, -5) into the equation:

Given: Point R (-1, -5), x = -1 and y = -5

Given: Line y = 2x - 3

Substitute: -5 = 2 (-1) - 3

Solve:        -5 = -2 - 3

                 -5 = -5 ---> Since this is TRUE, this means that Point R (-1, -5) is a solution to your equation/line, which supports the given that it lies on the line. Try solving for Point S. It should also give you a TRUE answer.

You now need to find out which of the three choices will also prove TRUE when substituted to the original equation:

Example:

Given: Point T (0, -3), x = 0 and y = -3

Given: Line y = 2x - 3

Substitute: -3 = 2 (0) - 3

Solve:        -3 = -3 ---> again, this is TRUE, which means that this is collinear (it lies on the same line as the first two points)

Try solving for the other two given points, Points U and V. You should try to practice and learn this kind of thing because this is nothing yet compared to what you'll be having in the next months or years.

Good luck!

Answer 2

For R:: -1 is X, -5 is Y. In seperate problems, replace -1 for x::[y=2(-1)-3] then -5 for y::: [-5=2x-3] and solve seperately.  THEN, do the same for S. Then with T, U, V. They are colinear if they lie on the line as well.

Answer 3

You should draw a graph with a X and Y axis on it. put a dot at the intersection of  X=-1, Y=-5 and X=3, Y=3. connect the dots with astraight line. You will see that  point T and U fall on that line. Point V does not fall on the line. Therefore T and U are colinear and V is not.

y=2x-3

-3=2(0)-3

-3=-3 therfore point T is colinear

y=2x-3

-4=2(-.5)-3

-4=-1-3

-4=-4 therefore point U is colinear

y=2x-3

-1=2(2)-3

-1=4-3

-1 does not= 1 therefore point v is not colinear.

don't forget to draw the graph.

Answer 4

This is actually rather simple. As you are given the equation of the line, you plug in the x and y coordinates into the equation:

T (0, -3)

-3 = 2(0) - 3

-3 = -3

Point T is collinear with R and S

U (-0.5, -4)

-0.5 = 2(-4) - 3

-0.5 = -8 - 3

-0.5 ≠ -11

Point U is NOT collinear with R and S

V (2, -1)

-1 = 2(2) - (-1)

-1 = 4 + 1

-1 ≠ 5

Point V is NOT collinear with R and S