Answer:
{x,y} = {3/7,-43/7}
Explanation:
System of Linear Equations entered :
[1] x + 3y = -18
[2] -x + 4y = -25
Graphic Representation of the Equations :
3y + x = -18 4y - x = -25
Solve by Substitution :
// Solve equation [1] for the variable x
[1] x = -3y - 18
// Plug this in for variable x in equation [2]
[2] -(-3y-18) + 4y = -25
[2] 7y = -43
// Solve equation [2] for the variable y
[2] 7y = - 43
[2] y = - 43/7
// By now we know this much :
x = -3y-18
y = -43/7
// Use the y value to solve for x
x = -3(-43/7)-18 = 3/7
Solution :
{x,y} = {3/7,-43/7}