System of three linear equations: aX + bY + cZ = d

For example:

2X + 3Y + 4Z = 119

5X - 6Y + 7Z = 80

8X + 9Y + 10Z = 353

You just need to enter

Equation 1) 2 3 4 119

Equation 2) 5 -6 7 80

Equation 3) 8 9 10 353

Result: X=12 Y=13 Z=14