System of Linear Equations entered :
[1] 5x + 10y = 5
[2] -13x + 4y=17
Solve by Substitution :
// Solve equation [2] for the variable y
[2] 4y = 13x + 17
[2] y = 13x/4 + 17/4
// Plug this in for variable y in equation [1]
[1] 5x + 10•(13x/4+17/4) = 5
[1] 75x/2 = -75/2
[1] 75x = -75
// Solve equation [1] for the variable x
[1] 75x = - 75
[1] x = - 1
// By now we know this much :
x = -1
y = 13x/4+17/4
// Use the x value to solve for y
y = (13/4)(-1)+17/4 = 1
Solution :
{x,y} = {-1,1}
