(x-y)^2 = (x+y)^2 - 4xy为什么是这样算的
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/02 19:57:01
![(x-y)^2 = (x+y)^2 - 4xy为什么是这样算的](/uploads/image/z/14889801-57-1.jpg?t=%28x-y%29%5E2+%3D+%28x%2By%29%5E2+-+4xy%E4%B8%BA%E4%BB%80%E4%B9%88%E6%98%AF%E8%BF%99%E6%A0%B7%E7%AE%97%E7%9A%84)
xRJ0} c`G Coڻtu8Q6p+2tYe.`~Qhn|?'jR0W-
LE (xi6쟩IoLdE~j)aɴbI4I0݀'JP;FM)ўILMo#7,R*8mx9\/"/#>7=?a$1@WVLiQӍgm&2$<Jb*.L]3%ޫbe ~Y@ |J k+ r
&@nJH ܌dqVZI.!]IlɩE2b֯/Y=+Pe1ɴCy_if
(x-y)^2 = (x+y)^2 - 4xy为什么是这样算的
(x-y)^2 = (x+y)^2 - 4xy为什么是这样算的
(x-y)^2 = (x+y)^2 - 4xy为什么是这样算的
左边=(x-y)^2 =x²+y²-2xy(完全平方差公式)
右边=(x+y)^2 - 4xy=x²+y²+2xy-4xy=x²+y²-2xy
∵等式左边等于右边
所以等式成立
楼主要知道这两个等式:
(a+b)²=a²+2ab+b² 或者(a-b)²=a²-2ab+b²
书上会学的
(x-y)^2
=x^2-2xy+y^2
=x^2+y^2-2xy
=x^2+2xy-2xy+y^2-2xy
=x^2+2xy+y^2-4xy
=(x+y)^2-4xy
(x+y)^2 - 4xy=(x-y)^2
x^2 +2xy+y^2 -4xy=(x-y)^2
x^2 -2xy+y^2=(x-y)^2
(x-y)^2=(x-y)^2
这个是恒等变形啊
你把两边展开,就相等了
x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2
填空:x-y/x+y=( )/x^2-y^2
(x-y)2•(y-x)³(x-y)=?
y+y'-2y=2x
微分方程y - 2y' + y = x
(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)=
(x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
化简y(x+y)+(x+y)(x-y)-x^2
(x-4y)(2x+y)=
(x+y)(2x-3y)=?
x+y>=2,x-y
x+y>=2,x-y
y'-2y=(e^x)-x
y'+2y/x=x通解
dy/dx=(2x*x*x*y-y*y*y*y)/(x*x*x*x-2x*y*y*y)
x²-(x-2y)(x+2y)+(x²-y)(y+x²)=?
(x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2