Vladimir says that the equation of the line that passes through points (-5,-3) and (10,9) is y=4/5x+1. Robyn says that the line passes through the points (-10,-7) and (-15,-11). Who is correct? a)only Vladimir b)only Robyn c)both Vladimir and Robyn d)neither Vladimir nor Robyn

Respuesta :

the slope given by Vladmir's points =  (9--3)/10--5) = 12/15 = 4/5
so its equation is 
y - y1 = (4/5)(x - x1)   where (x1,y1) = (10,9) giving:-
y - 9 = (4/5)(x - 10)
y = 4/5 x =1    which is the required equation 

So Vladimir is right.

Testing if  Robyn is right:-
Plug in his values:-
-7 = 4/5*-10  + 1
-7 = -7   so that point is on the line

-11 = (4/5) * -15 + 1
-11 = -11 so this point is also on the line

Answer:-  c) Both are right

The equation of a line is the equation that models the points on the line.

Both Vladimir and Robyn are correct

Vladimir's claim

The points are given as:

[tex]\mathbf{(x_1,y_1) = (-5,-3)}[/tex]

[tex]\mathbf{(x_1,y_1) = (10,9)}[/tex]

First, we calculate the slope (m)

[tex]\mathbf{m = \frac{y_2 - y_1}{x_2 - x_1}}[/tex]

So, we have:

[tex]\mathbf{m = \frac{9--3}{10--5}}[/tex]

[tex]\mathbf{m = \frac{12}{15}}[/tex]

Simplify

[tex]\mathbf{m = \frac{4}{5}}[/tex]

The equation is then calculated as:

[tex]\mathbf{y = m(x - x_1) + y_1)}[/tex]

So, we have:

[tex]\mathbf{y = \frac 45(x - -5) -3)}[/tex]

[tex]\mathbf{y = \frac 45(x+5) -3)}[/tex]

Open bracket

[tex]\mathbf{y = \frac 45x+4 -3)}[/tex]

[tex]\mathbf{y = \frac 45x+1}[/tex]

The above equation means that: Vladimir is right

Robyn's claim

We calculated the equation as:

[tex]\mathbf{y = \frac 45x+1}[/tex]

The points are given as:

[tex]\mathbf{(x,y) = (-10,-7)}[/tex]

[tex]\mathbf{(x,y) = (-15,-11)}[/tex]

Substitute these values in the equation.

[tex]\mathbf{(x,y) = (-10,-7)}[/tex]

[tex]\mathbf{y = \frac 45x+1}[/tex] becomes

[tex]\mathbf{-7 = \frac 45 \times -10 + 1}[/tex]

[tex]\mathbf{-7 = -8 + 1}[/tex]

[tex]\mathbf{-7 = -7}[/tex] -- this is true

[tex]\mathbf{(x,y) = (-15,-11)}[/tex]

[tex]\mathbf{y = \frac 45x+1}[/tex] becomes

[tex]\mathbf{-11 = \frac 45 \times -15 + 1}[/tex]

[tex]\mathbf{-11 = -12 + 1}[/tex]

[tex]\mathbf{-11 = -11}[/tex] -- this is also true

The above equations mean that: Robyn is also right

Hence, both Vladimir and Robyn are correct

Read more about equations of straight lines at:

https://brainly.com/question/21627259