Question

Solve for X and y: X+y=8,2x-3y=1

Answer 1

// Solve equation [1] for the variable x

[1] x = y + 8

// Plug this in for variable x in equation [2]

[2] -2•(y +8) - 3y = -1

[2] - 5y = 15

// Solve equation [2] for the variable y

[2] 5y = - 15

[2] y = - 3

// By now we know this much :

x = y+8

y = -3

// Use the y value to solve for x

x = (-3)+8 = 5

Solution :

{x,y} = {5,-3}