ayala is making salad dressing. she mixes oil and vinegar in a blender until a smooth consistency is formed…

Brief Explanations:

A homogeneous mixture has uniform composition throughout. When Ayala mixes oil and vinegar until smooth, they don't truly dissolve in each other (oil is non - polar and vinegar is polar). There are still distinct regions of oil and vinegar on a microscopic level, so it's not uniform. A heterogeneous mixture has non - uniform composition. Thus, this is a heterogeneous mixture.

Answer:

This is a heterogeneous mixture because oil and vinegar do not dissolve in each other completely and there are distinct regions of each component even when smooth - looking, indicating non - uniform composition.