Help.. solve using substitution??

Question

ok i got an answer to this but want to check if it is right.

solve using substitution

8x + 2y = -2

y = -x + 1

I got X = 0 and Y = 1

is this right I haven't dont this type of problem in like two years

Answer 1

8x+2y=-2 (1)

y=-x+1 (2)

The equation (2) gives y in function of x.

We can use (2) in (1).

8x+2(-x+1)=-2

8x-2x+2=-2

6x=-4

x=-4/6

x=-2/3

y=5/3

Answer 2

8x + 2(-x+1) = -2

8x - 2x + 2 = -2

6x = -4

x = -2/3

y = 2/3 + 1

=5/3

Answer 3

8x+2y=-2 (1)

y=-x+1  (2)

sub (2) in(1)) >8x+2(-x+1) >8x-2x+2=-2 >6x+2=-2>x=-4/6=-2/3

if x=-2/3 then sub  in(2) >y=-(-2/3)+1 =2/3+1=5/3

x=-2/3 and y=5/3

Answer 4

For this type of problem you will substitute in the given value of "y". In your case y=-x+1. So the way to solve this is as follows.

8x+2(-x+1)=-2

8x-2x+2=-2

6x=-4<---(here you will move the pos. two over to isolate x)

divide

x=-4/6

Now all you have to do is go back through and find y

Good luck!!!

Answer 5

y = -x + 1

8x + 2(-x + 1) = -2

8x - 2x + 2 = -2

6x = -4

x = -2/3

go back to any of the equations and plug in the x value found

y = - (-2/3) + 1

y = 2/3 + 1

y = 5/3

Answer 6

8x + 2(-x + 1) = -2

8x - 2x + 2 = -2

6x = -2 -2

6x = -4

x = -4/6

y = 4/6 + 1

y = 4/6 + 6/6

y = 10/6 = 5/3

x = -2/3

Answer 7

No, if X is 0, then Y must be -1

8 x 0 = 0

2 x -1 = -2

Answer 8

OK

Using substitution:

8x + 2y = -2

y = -x + 1 (which is the same as 1-x)

8x + 2(1-x) = -2

8x + 2 - 2x = -2

8x -2x = -4

6x = -4

x = -4/6

x = -2/3

Now substitute back

y = 1 - (-2/3)

y = 1 2/3

So , x = -2/3 and y = 1 2/3

Check

8(-2/3) + 2(1 2/3) = -2 ??

-16/3 + 10/3 = -2 ??

-6/3 = -2 ??

-2 = -2 YES!!

Hope that helps.  

Answer 9

8x+2y=-2                                  

y=-x+1                                        

8x+2(-x+1)=-2

8x-2x+2=-2

6x=-4

x=2/3     so,              

y=-(2/3)+1

  y=1/3