Question
Evaluate using the expansion of $(a + b)^2$ or $(a – b)^2: (20.7)^2$
✓
Answer
$(20.7)^2 = (20 + 0.7)^2$
$= (20)^2 + (0.7)^2 + 2 (20) (0.7)$
$= 400 + 0.49 + 28$
$= 428 + 0.49$
$= 428.49$
$= (20)^2 + (0.7)^2 + 2 (20) (0.7)$
$= 400 + 0.49 + 28$
$= 428 + 0.49$
$= 428.49$
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