Question

For the following system, if you isolated x in the second equation to use the Substitution Method, what expression would you substitute into the first equation?

2x + y = 8
-x - 3y = -12

Answer 1

@DangerousJesse

Answer 2

I closed this. can you just give me the ansers?

Answer 3

3y + 12

-3y + 12

3y - 12

-3y - 12

Answer 4

I'm just going to copy my answer from the previous question.. Solve the following system:
{2 y-x = -6
3 x+y = 8
Choose an equation and a variable to solve for.
In the second equation, look to solve for y:
{2 y-x = -6
3 x+y = 8
Solve for y.
Subtract 3 x from both sides:
{2 y-x = -6
y = 8-3 x
Perform a substitution.
Substitute y = 8-3 x into the first equation:
{2 (8-3 x)-x = -6
y = 8-3 x
Expand the left hand side of the equation 2 (8-3 x)-x = -6.
2 (8-3 x)-x = (16-6 x)-x = 16-7 x:
{16-7 x = -6
y = 8-3 x
Choose an equation and a variable to solve for.
In the first equation, look to solve for x:
{16-7 x = -6
y = 8-3 x
Isolate terms with x to the left hand side.
Subtract 16 from both sides:
{-7 x = -22
y = 8-3 x
Solve for x.
Divide both sides by -7:
{x = 22/7
y = 8-3 x
Perform a back substitution.
Substitute x = 22/7 into the second equation

Answer 5

It's giving an example, not an answer.

Answer 6

Answer?