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Consider this polynomial, where a is an unknown real number.

correctly/incorrectly
and why

Consider this polynomial, where a is an unknown real number. correctly/incorrectly-example-1
User BNazaruk
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1 Answer

6 votes

9514 1404 393

Answer:

  • incorrectly; used 1 in the division instead of -1
  • incorrectly; evaluated higher powers of -1 incorrectly

Explanation:

The result each should have obtained is ...

a +10 = 17

a = 7

Braulio's mistake was in using 1 as his divisor instead of -1. His bottom row should have been 1, 4, a-4, 1-a, a +10.

Zahra's mistake was improperly evaluating higher powers of -1. Her evaluation should have been 1 -5 +a +3 +11 = a +10.

User Vlado
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