计算:(1)16(y+3)²(y-3)²-(2y+1)²(2y-1)²(2)(2
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/18 05:22:00
计算:(1)16(y+3)²(y-3)²-(2y+1)²(2y-1)²(2)(2x+y-5z)(2x+y+5z)
(1)16(y+3)²(y-3)²-(2y+1)²(2y-1)²
=16[(y+3)(y-3)]²-[(2y+1)(2y-1)]²
=16(y²-9)²-(4y²-1)²
=16(y的4次方-18y²+81)-(16y的4次方-8y²+1)
=-280y²+1295
(2)(2x+y-5z)(2x+y+5z)
=[(2x+y)-5z][(2x+y)+5z]
=(2x+y)²-25z²
=4x²+4xy+y²-25z²
=16[(y+3)(y-3)]²-[(2y+1)(2y-1)]²
=16(y²-9)²-(4y²-1)²
=16(y的4次方-18y²+81)-(16y的4次方-8y²+1)
=-280y²+1295
(2)(2x+y-5z)(2x+y+5z)
=[(2x+y)-5z][(2x+y)+5z]
=(2x+y)²-25z²
=4x²+4xy+y²-25z²
运用乘法公式计算:(1)(x-y)(x+y)-(2x-y)²
先化简再求值:(x-2y)²-(x+2y)(x-2y)-(x-3y)(x-y).其中x²+9y
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
数学用乘法公式计算(x+y+1)(x+y-1)(2x-y-3)²
计算:(1)2/(x+y)+4y/x²-y²(2)x²/x+y-x+y
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
把方程(2y+1)(3y-2)=y²+2化成一般形式
计算:(x+2y)(3x-5y)-(6x的四次方y²-2x²y²)÷(2x²y&
计算6x³y^6÷(1/2)y³÷(-3x²y)-(12x^4y^6-8x²y^
计算(1)3x/8y×16y²/27x² (2)(2xy-x²)÷x-2y/xy 2x-6
(1):(x+2y)²-(x+y)(3x-y) (2):(2x+3y)²-(2x-3y)²