Problem: 8+18=\sqrt{8}+\sqrt{18}=8​+18​=
Answer Choices:
A. 26\sqrt{26}26​
B. 2(2+3)2(\sqrt{2}+\sqrt{3})2(2​+3​)
C. 777
D. 525 \sqrt{2}52​
E. 2132 \sqrt{13}213​
Solution:
8+18=4⋅2+9⋅2=22+32=52\begin{aligned} \sqrt{8}+\sqrt{18} & =\sqrt{4 \cdot 2}+\sqrt{9 \cdot 2} \\ & =2 \sqrt{2}+3 \sqrt{2}=5 \sqrt{2} \end{aligned} 8​+18​​=4⋅2​+9⋅2​=22​+32​=52​​