Question
Find the square of $391$
✓
Answer
$(319)^2$
$ = (400 − 9)^2= (400)^2 + 9^2 + 2 (400) (9)$
$= 160000 + 81 − 7200$
$= 152881$
$ = (400 − 9)^2= (400)^2 + 9^2 + 2 (400) (9)$
$= 160000 + 81 − 7200$
$= 152881$
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