Question

ANSWER QUICK!! 75 PTS!!!

Solve the system by substitution. Show your work.
2) -2x - 3y=-2
y=2x+6

Solve the system by elimination. Show your work.

3) -x - 18 = -3
7x - 9 = 21

Answer 1

2) x = -2 , y = 2

3) no solution exists

Explanation:

Solve the following system:

{-2 x - 3 y = -2

y = 2 x + 6

Hint: | Perform a substitution.

Substitute y = 2 x + 6 into the first equation:

{-2 x - 3 (2 x + 6) = -2

y = 2 x + 6

Hint: | Expand the left hand side of the equation -2 x - 3 (2 x + 6) = -2.

-2 x - 3 (2 x + 6) = (-6 x - 18) - 2 x = -8 x - 18:

{-8 x - 18 = -2

y = 2 x + 6

Hint: | Choose an equation and a variable to solve for.

In the first equation, look to solve for x:

{-8 x - 18 = -2

y = 2 x + 6

Hint: | Isolate terms with x to the left hand side.

Add 18 to both sides:

{-8 x = 16

y = 2 x + 6

Hint: | Solve for x.

Divide both sides by -8:

{x = -2

y = 2 x + 6

Hint: | Perform a back substitution.

Substitute x = -2 into the second equation:

Answer: {x = -2 , y = 2