(2,1 • 3,2 - 0,72) х = 5,4.

To solve the equation (2.1 • 3.2 - 0.72) x = 5.4, we first need to simplify the expression on the left side:

2.1 • 3.2 = 6.72 6.72 - 0.72 = 6

So the equation simplifies to:

6x = 5.4

Now, to solve for x, we divide both sides by 6:

x = 5.4 / 6 x = 0.9

Therefore, the solution to the equation is x = 0.9.