9514 1404 393
Answer:
- incorrectly; used 1 in the division instead of -1
- incorrectly; evaluated higher powers of -1 incorrectly
Step-by-step 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.
