hzb53jl55v的部落格

標題:

有5題maths a0a 好易 Q,2,4,5 XXX

發問:

1B [IMG]http://i164.photobucket.com/albums/u4/ming21ki/IMG_0009-13.jpg[/IMG] 1B , A [IMG]http://i164.photobucket.com/albums/u4/ming21ki/IMG_0015-7.jpg[/IMG] 1,2 [IMG]http://i164.photobucket.com/albums/u4/ming21ki/IMG_0018-9.jpg[/IMG]

最佳解答:

• 請問我五行屬甚麼-
• 林子善究竟結左婚未---@1@
• 張德蘭幾歲-

• 請問我五行屬甚麼-
• 林子善究竟結左婚未---@1@
• 張德蘭幾歲-

此文章來自奇摩知識+如有不便請留言告知

[Set 1] 1. (b) (2x+3)^2 - 25 = 0 (2x+3)^2 = 25 2x+3 = ±5 2x = -3±5 x = 1 or x = -4 [Set 2] 1. (a) Discriminant = (7)^2 - 4(5)(-k) = 49 + 20k (b) The equation has two equal real roots, discriminant = 0. 49 + 20k = 0 20k = -49 k = -49/20 [Set 3] 1. Discriminant = (3)^2 - 4(4)(-k) = 9 + 16k If the equation has no real roots, discriminant
其他解答:

B (2x+3)^2-25=0 (2x+8)(2x-2)=0 2x+8=0 OR 2x-2=0 x=-4 OR x=1