Question

Using radicals as needed, multiply
(sqrt7 +1)(8sqrt7 +1)

Answer 1

\[(\sqrt7 +1) (8\sqrt7 +1)\]

Answer 2

\[(\sqrt{7}+1)(8\sqrt{7} +1) \]



\[(\sqrt{7})(8\sqrt{7})+(\sqrt{7})(1)+(1)(8\sqrt{7})+1*1 \]



\[8\sqrt{7*7}+\sqrt{7}+8\sqrt{7}+1\]



\[8\sqrt{49}+\sqrt{7}+8\sqrt{7}+1\]



\[8(7)+\sqrt{7}+8\sqrt{7}+1\]



\[56+\sqrt{7}+8\sqrt{7}+1\]



\[57+9\sqrt{7}\]



So \[(\sqrt{7}+1)(8\sqrt{7} +1) = 57+9\sqrt{7} \]