| ( | X | + | 585 | ) | ÷ | ( | 1187 | + | X | ) | = | 3 4 |
| Multiply both sides of the equation by: | ( | 1187 | + | X | ) |
| ( | X | + | 585 | ) | = | 3 4 | ( | 1187 | + | X | ) |
| X | + | 585 | = | 3 4 | ( | 1187 | + | X | ) |
| X | + | 585 | = | 3 4 | × | 1187 | + | 3 4 | X |
| X | + | 585 | = | 3561 4 | + | 3 4 | X |
| X | − | 3 4 | X | = | 3561 4 | − | 585 |
1 4 | X | = | 3561 4 | − | 585 |
1 4 | X | = | 1221 4 |
| X | = | 1221 4 | ÷ | 1 4 |
| = | 1221 4 | × | 4 |
| = | 1221 | × | 1 |
| X | = | 1221 |