To solve this, we need to distribute the (-1/2) to each term in the equation:

(-1/2)(9х) - (-1/2)(3.6) = -7х + 2 1/2

-9х/2 + 3.6/2 = -7х + 2 1/2

-4.5х + 1.8 = -7х + 2 1/2

Now, we need to isolate the variable х. Let's move all terms involving х to the left side and constants to the right side:

-4.5х + 7х = 2 1/2 - 1.8

2.5х = 0.7

Now, we can solve for х by dividing both sides by 2.5:

х = 0.7 / 2.5

х = 0.28

Therefore, the solution to the equation (9х-3.6)*(-1/2) = -7х + 2 1/2 is х = 0.28.