Toán Lớp 8: 2x^2+2xy-x-y x^2-2xy-x^2+4x^2 x^2+2x+1-16 x^2-5x-6 x^2+6x+8 x^7+x^2+1

Question

Toán Lớp 8:  2x^2+2xy-x-y x^2-2xy-x^2+4x^2 x^2+2x+1-16 x^2-5x-6 x^2+6x+8 x^7+x^2+1

dantam45 · Answer

Giải đáp + Lời giải và giải thích chi tiết:    2x^2 + 2xy-x-y   = 2x(x+y)-(x+y)   = (x=y)(2x-1)                   x&sup2;-2xy-x^2+4x^2                  = 4x^2-2xy                  = 2x(2x-y)   x^2+2x+1-16   = (x+1)&sup2;-4^2   = (x+1-4)(x+1+4)   = (x-3)(x+5)                   x&sup2;-5x-6                   = x&sup2; +x-6x-6                   = x(x+1)-6(x+1)                   = (x+1)(x-6)   x&sup2;+6x+8   = x&sup2;+4x+2x+8   = x(x+4)+2(x+4)   = (x+4)(x+2)

thanoanghha · Answer

Giải đáp:     2x^2+2xy-x-y   = 2x(x+y)-(x+y)   = (x+y)(2x-1)   $  $   x^2-2xy-x^2+4x^2   = -2xy+4x^2   = 2x(2x-y)   $  $   x^2+2x+1-16   = (x+1)^2-4^2   = (x+1+4)(x+1-4)   = (x+5)(x-3)   $  $   x^2-5x-6   = x^2-6x+x-6   = x(x-6)+(x-6)   = (x-6)(x+1)   $  $   x^2+6x+8   = x^2+4x+2x+8   = x(x+4)+2(x+4)   = (x+4)(x+2)   $  $   x^7+x^2+1   = x^7+x^6-x^6+x^5-x^5-x^4+x^4+x^3-x^3+x^2-x^2-x+x+1   = x^5(x^2+x+1)-x^4(x^2+x+1)+x^2(x^2+x+1)-x(x^2+x+1)+(x^2+x+1)   = (x^2+x+1)(x^5-x^4+x^2-x+1)