Question

2 - Calcule o valor da expressão com radicais:

Answer 1

$\sqrt{\dfrac{81}{4}}-\sqrt{400}+2,25\\ \\ =\dfrac{\sqrt{81}}{\sqrt{4}}-\sqrt{20^{2}}+2,25\\ \\ =\dfrac{\sqrt{9^{2}}}{\sqrt{2^{2}}}-20+2,25\\ \\ =\dfrac{9}{2}-20+2,25\\ \\ =\dfrac{9-40+4,50}{2}\\ \\ =\dfrac{-26,50}{2}\\ \\ =-13,25$