Answer:
x = -5 , y = 2
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