( | 14 | − | 8 | − | x | ) | ( | 400 | − | 40 | x | ) | = | 1920 |
Left side of the equation = | 14 | ( | 400 | − | 40 | x | ) | − | 8 | ( | 400 | − | 40 | x | ) | − | x | ( | 400 | − | 40 | x | ) |
= | 14 | × | 400 | − | 14 | × | 40 | x | − | 8 | ( | 400 | − | 40 | x | ) | − | x | ( | 400 | − | 40 | x | ) |
= | 5600 | − | 560 | x | − | 8 | ( | 400 | − | 40 | x | ) | − | x | ( | 400 | − | 40 | x | ) |
= | 5600 | − | 560 | x | − | 8 | × | 400 | + | 8 | × | 40 | x | − | x | ( | 400 | − | 40 | x | ) |
= | 5600 | − | 560 | x | − | 3200 | + | 320 | x | − | x | ( | 400 | − | 40 | x | ) |
= | 2400 | − | 240 | x | − | x | ( | 400 | − | 40 | x | ) |
= | 2400 | − | 240 | x | − | x | × | 400 | + | x | × | 40 | x |
= | 2400 | − | 640 | x | + | x | × | 40 | x |
2400 | − | 640 | x | + | x | × | 40 | x | = | 1920 |