contestada

The two lines y=6x+15 and y=mx-4 intersect at x=-2 what is the y-coordinate of their intersection point? What is the value of m?

Respuesta :

Answer:

y=3 and m=[tex]-\frac{7}{2}[/tex].

Step-by-step explanation:

We are given two lines y=6x+15 and y=mx-4.

x-coordinate of the intersection point is x=-2.

In order to find the y-coordinate of intersection point, we need to plug x=-2 in first equation.

Plugging x=-2 in y=6x+15, we get

y=6(-2)+15

y=-12+15

y=3.

Therefore, y-coordinate of the intersection point is y=3.

Now, in order to find the value of m, we need to plug x and y-coordinate values in second equation and solve for m.

Plugging x=-2 and y=3 in second equation y=mx-4, we get

3=m(-2)-4

3 = -2m -4

Adding 4 on both sides, we get

3+4=-2m-4+4

7=-2m.

Dividing both sides by -2, we get.

[tex]\frac{7}{-2} =\frac{-2m}{-2}[/tex]

[tex]-\frac{7}{2}=m[/tex]

Therefore, m=[tex]-\frac{7}{2}[/tex].