Question
Answer
$$(\sqrt{7}-\sqrt{5})(\sqrt{7}+\sqrt{5})=2$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(\sqrt{7}-\sqrt{5})(\sqrt{7}+\sqrt{5})& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}7+\sqrt{35}-\sqrt{35}-5 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}2\end{aligned} $$ | |
| ① | $$ \color{blue}{ \left( \sqrt{7}- \sqrt{5}\right) } \cdot \left( \sqrt{7} + \sqrt{5}\right) = \color{blue}{ \sqrt{7}} \cdot \sqrt{7}+\color{blue}{ \sqrt{7}} \cdot \sqrt{5}\color{blue}{- \sqrt{5}} \cdot \sqrt{7}\color{blue}{- \sqrt{5}} \cdot \sqrt{5} = \\ = 7 + \sqrt{35}- \sqrt{35}-5 $$ |
| ② | Combine like terms |
This page was created using
Simplify Radical Expression