If you would like to solve the equation 2.5 * x - 10.5 = 64 * 0.5 * x, you can calculate this using the following steps:
2.5 * x - 10.5 = 64 * 0.5 * x
2.5 * x - 10.5 = 32 * x
- 10.5 = 32 * x - 2.5 * x
- 10.5 = 29.5 * x
x = - 10.5 / 29.5
x = - 0.3559 = - 0.36