Answer:

Step-by-step explanation:
The distributive law states that

The expression 3+21a+15b consists of three terms:
- 3=3·1;
- 21a=3·7a;
- 15b=3·5b.
You can see that 3 is the common factor of these three terms, thus

I believe it’s
D.51is it B ??
Answer:
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Step-by-step explanation:
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Thanks for free points :)
Answer+Step-by-step explanation:
