Solve the system of equations by using substitution. y = –2x – 3 x + y = 9

Step-by-step explanation:

x-2x-3=9

-x=9+3

-x=12

x=12/-1

x=-12

the coordinates of y are (1,-4)

Step-by-step explanation:

by using midpoint formula

z(x,y)=(,)

putting the values of coordinates

(3,-1)=,

separating the coordinates

3=                and           -1=

3×2=5+a                and      -1×2=2+b

6=5+a                  and        -2=2+b

6-5=a                    and          -2-2=b

1=a                            and            -4=b

so the actual coordinates of y are (1,-4)

i hope it will help you