First, simplify both sides of the equation:

-3(x-2)+4*(1+2x) = 10.3 + 20x
-3x + 6 + 4 + 8x = 10.3 + 20x
5x + 10 = 10.3 + 20x

Next, isolate the variable x by moving the terms with x to one side of the equation:

5x + 10 - 20x = 10.3
-15x + 10 = 10.3

Subtract 10 from both sides:

-15x = 0.3

Divide by -15 to solve for x:

x = -0.02

Therefore, the solution to the equation is x = -0.02.