3. How would the meaning of this sentence change if the writer removed the
commas?
The speaker, who used logos brilliantly, failed to persuade most
members of the audience because he did not make any effective
pathos or ethos appeals.

The sentence would turn into a run on sentence which means when you're reading the sentence it would feel like the sentence goes on forever and forever.

Explanation:

racism is the belief in the superiority of one race over another, which often results in discrimination and prejudice towards people based on their race or ethnicity. the use of the term "racism" does not easily fall under a single definition.

explanation:

3 is blunder, i’m not sure about the last one but the first two look correct