问初一题目啊啊!!急急急
来源:百度知道 编辑:UC知道 时间:2024/05/28 03:52:15
计算
{不是因式分解}
(x-1/2)(x^2+1/4)(x+1/2)
(-1-4a^2)
(2x-3y-1)(2x+3y-1)
先化简后求值
(x-5y)(-x-5y)-(-x+5y)^2
x=0.5 y=-1
要过程
满意加悬赏
明天交了!!谢谢啊!!
{不是因式分解}
(x-1/2)(x^2+1/4)(x+1/2)
(-1-4a^2)
(2x-3y-1)(2x+3y-1)
先化简后求值
(x-5y)(-x-5y)-(-x+5y)^2
x=0.5 y=-1
要过程
满意加悬赏
明天交了!!谢谢啊!!
(x-1/2)(x²+1/4)(x+1/2)
=(x-1/2)x+1/2))(x²+1/4)
=(x²-1/4)(x²+1/4)
=x^4-1/16,
(-1-4a^2)这个已经计算好了吧~~
(2x-3y-1)(2x+3y-1)
=(2x-1-3y)(2x-1+3y)
=(2x-1)²-(3y)²
=4x²-4x+1-9y²
先化简后求值
(x-5y)(-x-5y)-(-x+5y)^2
x=0.5 y=-1
(x-5y)(-x-5y)-(-x+5y)^2
=-(x-5y)(x+5y)-(x-5y)²
=-x²+25y²-x²+10xy-25y²
=-2x²+10xy
=-2×0.5²+10×0.5×(-1)
=-2×0.25-5
-0.5-5
=-5.5