Perform the indicated operation.
-$(\sqrt{8}+\sqrt{7})(\sqrt{8}-\sqrt{7})$
A) 1
B) 15
C) $8-4 \sqrt{28}$
D) $8-2 \sqrt{56}$

Name: Perform the indicated operation. -$(\sqrt{8}+\sqrt{7})(\sqrt{8}-\sqrt{7})$ A) 1 B) 15 C) $8-4 \sqrt{28}$ D) $8-2 \sqrt{56}$
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Question

Quizplus · Accepted Answer

This is an application of the difference of squares formula, $a^2 - b^2 = (a+b)(a-b)$. Here, $a = \sqrt{8}$ and $b = \sqrt{7}$, so the expression simplifies to $\sqrt{8}^2 - \sqrt{7}^2 = 8 - 7 = 1$.

Perform the Indicated Operation (8+7)(8−7)(\sqrt{8}+\sqrt{7})(\sqrt{8}-\sqrt{7})(8​+7​)(8​−7​) A) 1 B) 15 C) 8−4288-4 \sqrt{28}8−428​

Perform the Indicated Operation $(\sqrt{8}+\sqrt{7})(\sqrt{8}-\sqrt{7})$ A) 1
B) 15
C) $8-4 \sqrt{28}$