4 | ( | 20 | ( | t | + | 2 | ) | + | 30 | t | ) | + | 25 | × | 3 | t | + | 30 | × | 3 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 6 | × | 20 | = | 500 | t | + | 400 |
Left side of the equation = | 4 | ( | 20 | ( | t | + | 2 | ) | + | 30 | t | ) | + | 75 | t | + | 90 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
= | 4 | ( | 20 | ( | t | + | 2 | ) | + | 30 | t | ) | + | 165 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
4 | ( | 20 | ( | t | + | 2 | ) | + | 30 | t | ) | + | 165 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 | = | 500 | t | + | 400 |
Left side of the equation = | 4 | × | 20 | ( | t | + | 2 | ) | + | 4 | × | 30 | t | + | 165 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
= | 80 | ( | t | + | 2 | ) | + | 120 | t | + | 165 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
= | 80 | ( | t | + | 2 | ) | + | 285 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
= | 80 | t | + | 80 | × | 2 | + | 285 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
= | 80 | t | + | 160 | + | 285 | t | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
= | 365 | t | + | 160 | + | ( | t | + | 2 | + | 3 4 | ) | × | 120 |
= | 365 | t | + | 160 | + | t | × | 120 | + | 2 | × | 120 | + | 3 4 | × | 120 |
= | 365 | t | + | 160 | + | t | × | 120 | + | 240 | + | 90 |
= | 485 | t | + | 490 |
485 | t | + | 490 | = | 500 | t | + | 400 |
485 | t | − | 500 | t | = | 400 | − | 490 |
- | 15 | t | = | 400 | − | 490 |
- | 15 | t | = | - | 90 |
90 | = | 15 | t |
15 | t | = | 90 |
t | = | 90 | ÷ | 15 |
= | 90 | × | 1 15 |
= | 6 | × | 1 |
t | = | 6 |