Question

2x + y = -8 3x - 5y = -25 It’s substitution

Answer 1

Answer:

x = -5 , y = 2

Step-by-step explanation:

Solve the following system:

{y + 2 x = -8

-5 y + 3 x = -25

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

In the first equation, look to solve for y:

{y + 2 x = -8

-5 y + 3 x = -25

Hint: | Solve for y.

Subtract 2 x from both sides:

{y = -2 x - 8

-5 y + 3 x = -25

Hint: | Perform a substitution.

Substitute y = -2 x - 8 into the second equation:

{y = -2 x - 8

3 x - 5 (-2 x - 8) = -25

Hint: | Expand the left hand side of the equation 3 x - 5 (-2 x - 8) = -25.

3 x - 5 (-2 x - 8) = (10 x + 40) + 3 x = 13 x + 40:

{y = -2 x - 8

13 x + 40 = -25

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

In the second equation, look to solve for x:

{y = -2 x - 8

13 x + 40 = -25

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

Subtract 40 from both sides:

{y = -2 x - 8

13 x = -65

Hint: | Solve for x.

Divide both sides by 13:

{y = -2 x - 8

x = -5

Hint: | Perform a back substitution.

Substitute x = -5 into the first equation:

{y = 2

x = -5

Hint: | Sort results.

Collect results in alphabetical order:

Answer: {x = -5 , y = 2