To solve this equation, we first need to distribute the negative sign on the second parenthesis:

7,1x - 6,3 - 6,7x + 7,9 = 0

Next, combine like terms by adding the x terms and the constant terms separately:

7,1x - 6,7x - 6,3 + 7,9 = 0
(7,1 - 6,7)x + (-6,3 + 7,9) = 0
0,4x + 1,6 = 0

Now, we subtract 1,6 from both sides to isolate x:

0,4x = -1,6

Finally, divide both sides by 0,4 to find the value of x:

x = -1,6 / 0,4
x = -4

Therefore, the solution to the equation (7,1x - 6,3) - (6,7x - 7,9) = 0 is x = -4.