System of Linear Equations entered :
 [1] y - 2x/3 = -1
 [2] y + x = 4
// To remove fractions, multiply equations by their respective LCD
 Multiply equation [1] by 3
// Equations now take the shape:
 [1] 3y - 2x = -3
 [2] y + x = 4
Graphic Representation of the Equations :
 -2x + 3y = -3 x + y = 4 
 
 
Solve by Substitution :
// Solve equation [2] for the variable x 
 
 [2] x = -y + 4
// Plug this in for variable x in equation [1]
 [1] 3y - 2•(-y +4) = -3
 [1] 5y = 5
// Solve equation [1] for the variable y 
 [1] 5y = 5 
 [1] y = 1 
// By now we know this much :
 y = 1
 x = -y+4
// Use the y value to solve for x 
 x = -(1)+4 = 3 
I hope this help you