Answer:
[tex]\Huge \boxed{20}[/tex]
Explanation:
[tex]\sqrt{400}[/tex]
Rewriting 400 as 20².
[tex]\sqrt{20^2 }[/tex]
Cancelling the square root and the power.
[tex]20[/tex]
√400 = 20
√400 =
= √4×100
= √2²×10²
= √(2×10)²
= √20²
= 20