一些二次根试计算(1)(-5/根号下12)^2(2)根号下1/5除以根号下1/6(3)1/2+根号下3

Question

一些二次根试计算
(1)(-5/根号下12)^2 (2)根号下1/5除以根号下1/6 (3)1/2+根号下3

Answer 1

(1)(-5/根号下12)^2
=25/(根号下12)^2
=25/144
(2)(根号下1/5) / (根号下1/6)
=[(根号下1/5)* (根号下6)]/ [(根号下1/6)*(根号下6)]
=(根号下1/5)* (根号下6)
=[(根号下5)/5]* (根号下6)
=(根号下30)/5
(3)1/(2+根号下3)
=[1*(2-根号下3)]/[(2+根号下3)*(2-根号下3)]
=(2-根号下3)]/[4-3]
=(2-根号下3)]