WAEC - Mathematics (1998 - No. 57)
Evaluate \(\sqrt{20}\times (\sqrt{5})^3\)
10
20
25
50
คำอธิบาย
\(\sqrt{20}\times (\sqrt{5})^3\\
2\sqrt{5}\times \sqrt{5}\times \sqrt{5}\times \sqrt{5}=2\times 5\times 5 = 50\)
2\sqrt{5}\times \sqrt{5}\times \sqrt{5}\times \sqrt{5}=2\times 5\times 5 = 50\)