\(a,A=x^2(x-y^2)-xy(1-yx)-x^3\\=x^3-x^2y^2-xy+x^2y^2-x^3\\=(x^3-x^3)+(-x^2y^2+x^2y^2)-xy\\=-xy\\---\\b,B=x(x+3y+1)-2y(x-1)-(y+x+1)x\\=x^2+3xy+x-2xy+2y-xy-x^2-x\\=(x^2-x^2)+(3xy-2xy-xy)+(x-x)+2y\\=2y\\---\)
\(c,M=5x(x-5y)+(y-5x)(-5y)-1-5(x^2-y^2)\\=5x^2-25xy-5y^2+25xy-1-5x^2+5y^2\\=(5x^2-5x^2)+(-25xy+25xy)+(-5y^2+5y^2)-1\\=-1\\---\\d,(x^2y+x^3-xy^2+3)+(x^3+xy^2-xy-6)\\=x^2y+x^3-xy^2+3+x^3+xy^2-xy-6\\=x^2y+(x^3+x^3)+(-xy^2+xy^2)-xy+(3-6)\\=x^2y+2x^3-xy-3\\\text{#}Toru\)
Đúng 1
Bình luận (0)
