Question

(b) Work out the value of (√2+√8)^2
​

Answer 1

`~~~\left(\sqrt 2 + \sqrt 8 \right)^2\\\\=\left(\sqrt 2 \right)^2 + \left(\sqrt 8 \right)^2 +2 \sqrt 2 \sqrt 8\\\\=2+8+2√(2 \cdot 8)\\\\=10+2√(16)\\\\=10+2(4)\\\\=10+8\\\\=18`