-8x+y=15 2x-2y=-2 solve by substitution

Question

solve by substitution need to know how to set up thank you

Answer 1

Hi Roseland,

 

-8x+y=15   equation 1

 

2x-2y=-2

  x-y=-1

  x=y-1     equation 2

 

put the value of equation 2 in equation 1

 

-8(y-1)+y=15

-8y+8+y = 15

-7y= 15-8

-7y=7

  y=-1

 

put the value of y=-1 in equation 2

 

x=-1-1

x=-2

 

so the solution is x=-2 and y=-1.

Answer 2

 -8X + Y = 15

 

   2X - 2Y = -2

 

   Solve X from 2nd equation:

 

     X = 2Y +2 = Y+1

              2

   I have solved 3 . I think you should follow the same procedure , and finish yourself to learn