Respuesta :
Answer:
The y-coordinate of their intersection point is 3
That is y=3
Step-by-step explanation:
Given two lines are y=6x+15 and y=mx+4
Given that the two lines intersect at x=-2
To find the y coordinate of their intersection point :
Equating the two lines
6x+15=mx+4
6x+15-mx-4=0
6x-mx+11=0
(6-m)x+11=0
At x=-2 (6-m)x+11=0
(6-m)(-2)+11=0
(6-m)(-2)=-11
[tex]6-m=\frac{11}{2}[/tex]
[tex]-m=\frac{11}{2}-6[/tex]
[tex]-m=\frac{11-12}{2}[/tex]
[tex]-m=\frac{-1}{2}[/tex]
[tex]m=\frac{1}{2}[/tex]
Substitute the value [tex]m=\frac{1}{2}[/tex] in y=mx+4 we get
[tex]y=\frac{1}{2}x+4[/tex]
At x=-2 [tex]y=\frac{1}{2}(-2)+4[/tex]
[tex]=-1+4[/tex]
[tex]=3[/tex]
Therefore y=3
Therefore the y-coordinate of their intersection point is 3
