Question
If $a = − 10$, evaluate:
$a^2 + 8a$
$a^2 + 8a$
✓
Answer
$a^2 + 8a$
$= (a \times a) + (8 \times a)$
$= (− 10 \times (− 10)) + (8 \times (− 10))$
$= 100 + (− 80)$
$= 100 − 80$
$= 20$
$= (a \times a) + (8 \times a)$
$= (− 10 \times (− 10)) + (8 \times (− 10))$
$= 100 + (− 80)$
$= 100 − 80$
$= 20$
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