( | 125 | − | a | ) | ( | 75 | + | a | ) | − | 70 | ( | 75 | + | 5 | a | ) | = | 0 |
Left side of the equation = | 125 | ( | 75 | + | a | ) | − | a | ( | 75 | + | a | ) | − | 70 | ( | 75 | + | 5 | a | ) |
= | 125 | × | 75 | + | 125 | a | − | a | ( | 75 | + | a | ) | − | 70 | ( | 75 | + | 5 | a | ) |
= | 9375 | + | 125 | a | − | a | ( | 75 | + | a | ) | − | 70 | ( | 75 | + | 5 | a | ) |
= | 9375 | + | 125 | a | − | a | × | 75 | − | a | a | − | 70 | ( | 75 | + | 5 | a | ) |
= | 9375 | + | 50 | a | − | a | a | − | 70 | ( | 75 | + | 5 | a | ) |
= | 9375 | + | 50 | a | − | a | a | − | 70 | × | 75 | − | 70 | × | 5 | a |
= | 9375 | + | 50 | a | − | a | a | − | 5250 | − | 350 | a |
= | 4125 | − | 300 | a | − | a | a |
4125 | − | 300 | a | − | a | a | = | 0 |