Câu 1: Rút gọn 1) A= ( 1- √5 ) . √5 + 5 / 2√5 Giúp mik chính xác nha :> 17/09/2021 Bởi Ximena Câu 1: Rút gọn 1) A= ( 1- √5 ) . √5 + 5 / 2√5 Giúp mik chính xác nha :>
$A= (1-\sqrt5).\dfrac{\sqrt5+5}{2\sqrt5}$ $=(1-\sqrt5).\dfrac{\sqrt5(1+\sqrt5)}{2\sqrt5}$ $= \dfrac{(1-\sqrt5)(1+\sqrt5)}{2}$ $=\frac{1-5}{2}=-2$ Bình luận
$A=(1-\sqrt[]5).\dfrac{\sqrt[]5+5}{2.\sqrt[]5}$$=(1-\sqrt[]5)\dfrac{\sqrt[]5(\sqrt[]5+1)}{2.\sqrt[]5}$ $=\dfrac{(1-\sqrt[]5)(\sqrt[]5+1)}{2}=\dfrac{\sqrt[]5-5+1-\sqrt[]5}{2}=\dfrac{-4}{2}=-2$ Bình luận
$A= (1-\sqrt5).\dfrac{\sqrt5+5}{2\sqrt5}$
$=(1-\sqrt5).\dfrac{\sqrt5(1+\sqrt5)}{2\sqrt5}$
$= \dfrac{(1-\sqrt5)(1+\sqrt5)}{2}$
$=\frac{1-5}{2}=-2$
$A=(1-\sqrt[]5).\dfrac{\sqrt[]5+5}{2.\sqrt[]5}$$=(1-\sqrt[]5)\dfrac{\sqrt[]5(\sqrt[]5+1)}{2.\sqrt[]5}$ $=\dfrac{(1-\sqrt[]5)(\sqrt[]5+1)}{2}=\dfrac{\sqrt[]5-5+1-\sqrt[]5}{2}=\dfrac{-4}{2}=-2$