Y=sin(x+b) is obtained, and the abscissa is reduced by 1/a times.

Get y=sin(ax+b).

②y=sinx is reduced by 1/a times to get y=sinax, and the image is shifted to the left by B to get y=sina(x+b)=sin(ax+ab).

Modified some of your original works,

1. The changed function is another function different from the original function and cannot be written as f(x), so y=… is enough.

2. The necessary brackets cannot be omitted.

3. When translating, image translation is used here, not abscissa translation.

Conclusion: Compare the two results.

①y=sin(ax+b)，②y=sin(ax+ab)，

Obviously different.