计算下列几道题★1.（2x+y-5z)(2x+y+5z)2.16(y+3)^2(y-3)^2-(2y+1)^2(2y-1)^23.(1/2x-1/3y)(1/2x+1/3y)(1/4x^2+1/9y^2)

计算下列几道题★1.（2x+y-5z)(2x+y+5z)2.16(y+3)^2(y-3)^2-(2y+1)^2(2y-1)^23.(1/2x-1/3y)(1/2x+1/3y)(1/4x^2+1/9y^2) 2(x+y-z)-3(x-y+z)-5(x+y-z)+6(x-y+z) 计算 合并下列各式的同类项 1.-(5x-y-2z)-3[4x-(x-y-z)+2y] 计算（x-y-z)^2 设有变量定义“intx=1,y=2,z=3 ；”,计算下列表达式的值1）（x=(float)(y)+0.5)/22) z=(- -x,y++,x+y+z)3) x=y=z4) x*=y-(z=1)5) x=(y++)+(--z)6) x%=(z/=2) 计算:x^2/(x-y)(x-z)+y^2/(y-x)(y-z)+z^2/(z-x)(z-y) 为了应用平方差公式计算(2x+y+z)(y-2x-z),下列变形正确的是 计算(2x+y+z)(2x-y-z), 计算(x+2y-z)(2y+z-x) 计算(x-2y+z)(z-x-2y), (x一2y+z)(-x+2y+z)(计算) 计算:(x+2y-z)(x-2y-z) 计算(x+2y-z)(2y+z-x) 计算：(x-y-z)^2-(x-y+z)^2 (x+2y-z)(x-2y-z)计算过程 计算：(x+2y-z)(x-2y+z) 计算:(y-x)(z-x)/(x-2y+z)(x+y-2z)+(z-y)(x-y)/(x+y-2z)(y+z-2x)+(x-z)(y-z)/(y+z-2x)(x-2y+z) x-y-z=-1,3x+5y+7z=11,4x-y+2z=-1.(解三元一次方程)要有计算过程!