Question
Simplify the following expression:
$(\sqrt{5}-\sqrt{2})(\sqrt{5}+\sqrt{2})$
$(\sqrt{5}-\sqrt{2})(\sqrt{5}+\sqrt{2})$
✓
Answer
$(\sqrt{5}-\sqrt{2})(\sqrt{5}+\sqrt{2})$
As we know, $(a+b)(a-b)=\left(a^2-b^2\right)$
$=\sqrt{5 \times 5}-\sqrt{2 \times 2}$
$=5-2$
$=3$
As we know, $(a+b)(a-b)=\left(a^2-b^2\right)$
$=\sqrt{5 \times 5}-\sqrt{2 \times 2}$
$=5-2$
$=3$
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