1.计算 (1) (5x-2y)^2+20xy (2)(x-3)^2(x+3)^2 (3) (3x-5)^2-(2x+7
计算:3xy[2xy-x(y-2)+x]
化简 (x+y)(x²-xy+y²) ; 3(2x-1)(x+6)-5(x-3)(x+6)
通分计算:(1)2x-3/(x-1)(x-4) - x-2/(1-x)(4-x) (2)x平方-y平方/xy - xy-
计算4xy+(x-2y)的平方+(x+3y)(3y-x)
计算(1)(-2x^2)^5/(-x^3)^3+(2x)^4(2)【5xy^2(x^2-3xy)-(-3x^2y^2)^
计算(3x^3y-x^2y+1/2xy)÷(-1/2xy)
计算:(-7x²y)(2x²y-3xy³+xy)
计算(1)x/x+y-x/x-y (2)a+2+4/a+2 (3)x^2-y^2/xy÷(x+y)
计算3x/8y×16y²/27x² (2xy-x²)÷x-2y/xy 2x-6/x
计算[3x分之2-(x+y分之2)乘以[3x分之x+(y-x^2-xy)]除以x分之x-y
计算(1)3x/8y×16y²/27x² (2)(2xy-x²)÷x-2y/xy 2x-6
计算:(1)(7-3x)+(5x-6) (2)-(x^2-3)-(7-5x^2) (3)xy-(3x-2xy)+(3xy