例计算: (1)32=√3?12=√36=6 (2)√288′ 288? 4=2 72 72 例化简 2 (1)√225=√1515=√15?√15=(15)=15
例题 计算: (2) (1) 3 12 ´ 1 288 72 ´ 例题 化简: (1) 225 = ?3 12 = 36 = 6 1 288 72 = ? = 4 = 2 = ? 15 15 ( ) 2 = ? 15 15 = 15 = 15 11
16,b2,c2, (2)√16b2c3是开得尽的因数或因式 =4a( 2 16a√b 4°√a·b 4。√abec √ =4bc√ac 12
(2) 2 3 16ab c 2 3 = 16 a b c 2 = 4 a b c c 2 = 4 a b c c = 4 a b c c = 4bc ac 16 , b 2 , c 2 , 是开得尽的因数或因式。 12
计算:一题多解→ (1)3√5′2√10 5′210 3创√510;=3创√5√5?2 =6√52?2 =3创√5√5?√2 63?V2}=3@(5)√5 6?5 6?52 =30 =30 13
例题 计算: (1) 3 5 2 10 ´ = 3 2 5 10 创 2 = ? 6 5 2 2 = ? 6 5 2 = ?6 5 2 = 30 2 3 5 2 10 ´ = 3 2 5 5 2 创 ? = 3 2 5 5 2 创 ? ( ) 2 = 3 2 5 2 创 = ?6 5 2 = 30 2 一题多解 13
(2)2√xy X 2,/Cyo x°√y 2√y 2√x 21x 题多解 2 14
(2) 1 2 xy x 1 2 xy x = = 2 y 1 2 xy x 1 2 x y x = 1 2 x y x = 1 2 x y x = = 2 y 一题多解 14