计算题,1：(x+1/2)^2+(x-1/2)^2+(x+1/2)(x-1/2)（1／3a-3/4b)^2-(1/3a+3/4b)^2填空：x^2+6x+_____=(x+3)^2x^2+____+9y^2=(x+3y)^2a^2+____+1/4=(a+1/2)^2x^2-8xy+___=(x-4y)^2(a+b)^2-____=(a-b)^2化简：（x+3y)^2+2(x-y)(x+y)+(x-3y)^2〔（a-1/2)^2+(a+
1人问答
更新时间:2024-04-25 21:39:08
问题描述：
计算题,1：(x+1/2)^2+(x-1/2)^2+(x+1/2)(x-1/2)
（1／3a-3/4b)^2-(1/3a+3/4b)^2
填空：x^2+6x+_____=(x+3)^2
x^2+____+9y^2=(x+3y)^2
a^2+____+1/4=(a+1/2)^2
x^2-8xy+___=(x-4y)^2
(a+b)^2-____=(a-b)^2
化简：（x+3y)^2+2(x-y)(x+y)+(x-3y)^2
〔（a-1/2)^2+(a+1/2)^2](2a^2-1/2)
(x+2y+3)^2-(x-2y+3)(x-2y-3)
李铁克回答：
1：(x+1/2)^2+(x-1/2)^2+(x+1/2)(x-1/2)
=x^2+x+1/4+x^2-x+1/4+x^2-1/4
=3x^2+1/4
（1／3a-3/4b)^2-(1/3a+3/4b)^2
=(1/3a-3/4b+1/3a+3/4b)(1/3a-3/4b-1/3a-3/4b)
=(2/3a)(-3/2b)
=-ab
填空：x^2+6x+__9___=(x+3)^2
x^2+__6xy__+9y^2=(x+3y)^2
a^2+__a__+1/4=(a+1/2)^2
x^2-8xy+_16y^2__=(x-4y)^2
(a+b)^2-__4ab__=(a-b)^2
化简：（x+3y)^2+2(x-y)(x+y)+(x-3y)^2
=x^2+6xy+9y^2-2x^2-2y^2+x^2-6xy+9y^2
=18y^2-2y^2
〔（a-1/2)^2+(a+1/2)^2](2a^2-1/2)
=(a^2-a+1/4+a^2+a+1/4)(2a^2-1/2)
=(2a^2+1/2)(2a^2-1/2)
=4a^2-1/4
(x+2y+3)^2-(x-2y+3)(x-2y-3)
=x^2+4y^2+9+4xy+6x+12y-[(x-2y)^2-9]
=x^2+4y^2+9+4xy+6x+12y-x^2+4xy-4y^2+9
=8xy+6x+12y+18
数学推荐
数学推荐
最新更新
精品分类
优秀数学推荐
热门数学
