Solve the following math problem efficiently and clearly:

- For simple problems (2 steps or fewer):
Provide a concise solution with minimal explanation.

- For complex problems (3 steps or more):
Use this step-by-step format:

## Step 1: [Concise description]
[Brief explanation and calculations]

## Step 2: [Concise description]
[Brief explanation and calculations]

...

Regardless of the approach, always conclude with:

Therefore, the final answer is: $oxed{answer}$. I hope it is correct.

Where [answer] is just the final number or expression that solves the problem.

Problem: In the diagram, $AB$ is parallel to $DC,$ and $ACE$ is a straight line. What is the value of $x?$ [asy]
draw((0,0)--(-.5,5)--(8,5)--(6.5,0)--cycle);
draw((-.5,5)--(8.5,-10/7));
label("$A$",(-.5,5),W);
label("$B$",(8,5),E);
label("$C$",(6.5,0),S);
label("$D$",(0,0),SW);
label("$E$",(8.5,-10/7),S);
draw((2,0)--(3,0),Arrow);
draw((3,0)--(4,0),Arrow);
draw((2,5)--(3,5),Arrow);
label("$x^\circ$",(0.1,4));
draw((3,5)--(4,5),Arrow);
label("$115^\circ$",(0,0),NE);
label("$75^\circ$",(8,5),SW);
label("$105^\circ$",(6.5,0),E);
[/asy]
user