(x-y-3)的平方简算方法
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/25 19:22:33
[(x+2y)^2-(x+y)(3x-y)-5y^2]/2x=(x^2+4xy+4y^2-3x^2-3xy+xy+y^2-5y^2)/2x=(-2x^2+2xy)/2x=-x+y=2+1/2=二分之五
x^2+y^2=19x^2+9y^2=93x-4y=93x=4y+99x^2+9y^2=9(4y+9)^2+9y^2=916y^2+72y+81+9y^2-9=025y^2+72y+72=0△
2(y-x)²-7(x-y)+6(x-y)-3(y-x)²=-(y-x)²-(x-y)=-(x-y)²-(x-y)=-(x-y)[(x-y)+1]=(y-x)(
(x-y)²(x+y)²=[(x-y)(x+y)]²=(x²-y²)²=x的4次方-2x²y²+y的4次方(x-y)
x/2=y/3设x=2k;y=3kx的平方-y的平方/x的平方-2xy-3y的平方=(4k²-9k²)/(4k²-12k²-27k²)=5/35=1/
3x的平方-【7y-2(4x的平方-y)-2x的平方】=3x²-[7y-8x²+2y-2x²]=3x²-7y+8x²-2y+2x²=13x&
先简化,再代入,(x-y)/(x-3y)=2/7,另外一个种,直接代入计算再问:详细一点。。。再答:x/2=y/3,那么y=3x/2,代入方程式,可以得出2/7(x^2-y^2)/(x^2-2xy-3
套用公式(a+b+c)2=a2+b2+c2+2ab+2ac+2bc(2x-y-3)=(2x)平方+(-y)平方+(-3)平方+2*2x*(-y)+2*2x*(-3)+2*(-y)*(-3)=4x平方+
=[2x²+(1-3y³)][2x²-(1-3y³)]=(2x²)²-(1-3y³)²=4x的4次方-1+6y³
2(x²y+xy)-3(x²y+xy)-4x²y=-(x²y+xy)-4x²y=-5x²y-xy=-xy(5x+1)=1×2(-5+1)=-
4xy的平方-4x的平方y-y的3次方=-y(4x²-4xy+y²)=-y(2x-y)²
x^2+2xy+y^2+3x+3y-4=(x+y)^2+3(x+y)-4完全平方公式加提取公因式=(x+y+4)(x+y-1)十字相乘法希望有所帮助
1,4x²y-2xy²-5xy²+2x²y=6x²y-7xy²;2,(x²-y²-2xy)-(-3x²+4xy
x(x-y)²-(y-x)³=x(x-y)²+(x-y)³=(x-y)²[x+(x-y)]=(x-y)²(2x-y)
x的平方-5x-14=0(x-7)(x+2)=0x1=7x2=-2(2y-1)的平方=3(2y-1)(2y-1)(2y-1-3)=02(2y-1)(y-2)=0y1=1/2y2=2
(1)十字相乘:(x-7)(x+2)=0,所以:x1=7,x2=-2;(2)移项,(2y-1)^2-3(2y-1)=0,(2y-1)(2y-4)=0,即(2y-1)(y-2)=0所以:y1=1/2,y
平方差原式=(x-y+2x+3y)(x-y-2x-3y)=(3x+2y)(-x-4y)=-(3x+2y)(x+4y)
(x-y)(x的平方+3xy+y的平方)-5xy(x-y)=(x-y)[(x^2+3xy+y^2)-5xy]=(x-y)(x-y)^2=(x-y)^3x=6.61,y=-3.39.所以原式=(6.61
配方法:y=x+2x+1+2=(x+1)+2≥2所以,最小值为2图像法:图像开口向上,对称轴x=-1x=-1时,y取得最小值2