( | x | − | 70 | ) | ( | 20 | + | 220 | − | 2 | x | ) | × | 7 | = | 1200 |
Left side of the equation = | x | ( | 20 | + | 220 | − | 2 | x | ) | × | 7 | − | 70 | ( | 20 | + | 220 | − | 2 | x | ) | × | 7 |
= | x | ( | 20 | + | 220 | − | 2 | x | ) | × | 7 | − | 490 | ( | 20 | + | 220 | − | 2 | x | ) |
= | x | × | 20 | × | 7 | + | x | × | 220 | × | 7 | − | x | × | 2 | x | × | 7 | − | 490 | ( | 20 | + | 220 | − | 2 | x | ) |
= | x | × | 140 | + | x | × | 1540 | − | x | × | 14 | x | − | 490 | ( | 20 | + | 220 | − | 2 | x | ) |
= | 1680 | x | − | x | × | 14 | x | − | 490 | ( | 20 | + | 220 | − | 2 | x | ) |
= | 1680 | x | − | x | × | 14 | x | − | 490 | × | 20 | − | 490 | × | 220 | + | 490 | × | 2 | x |
= | 1680 | x | − | x | × | 14 | x | − | 9800 | − | 107800 | + | 980 | x |
= | 2660 | x | − | x | × | 14 | x | − | 117600 |
2660 | x | − | x | × | 14 | x | − | 117600 | = | 1200 |