Question

calcule 2√8 - 4√18 +√32

Answer 1

$2\sqrt{8}-4\sqrt{18}+\sqrt{32}\\ \\ =2\sqrt{2^{2}\cdot 2}-4\sqrt{3^{2}\cdot 2}+\sqrt{2^{4}\cdot 2}\\ \\ =2\cdot \sqrt{2^{2}}\cdot \sqrt{2}-4\cdot \sqrt{3^{2}}\cdot \sqrt{2}+\sqrt{2^{4}}\cdot \sqrt{2}\\ \\ =2\cdot 2\cdot \sqrt{2}-4\cdot 3 \cdot \sqrt{2}+2^{2}\cdot \sqrt{2}\\ \\ =4\sqrt{2}-12\sqrt{2}+4\sqrt{2}\\ \\ =\left(4-12+4 \right )\sqrt{2}\\ \\ =-4\sqrt{2}$

Answer 2

$2 \sqrt{8} - 4 \sqrt{18} + \sqrt{32} \\ \\ \\ 2 \sqrt{2^3} + 4\sqrt{2*3^2} + \sqrt{2^5x}\\ \\ \\ 2*2 \sqrt{2} - 4*3 \sqrt{2} + 4 \sqrt{2} \\ \\ \\ 4 \sqrt{2} - 12 \sqrt{2} + 4 \sqrt{2} \\ \\ \\ 4 \sqrt{2} - 8\sqrt{2} \\ \\ \\ => -4 \sqrt{2}$