(5x^2+4x-11)-(-x^2-3x-10)+(2-7x-6x^2)
=5x^2+4x-11+x^2+3x+10+2-7x-6x^2
=(5x^2+x^2-6x^2)+(4x+3x-7x)+(-11+10+2)
=0+0+1=1
so,无论x为何值时,原始都永恒不变.
(5x^2+4x-11)-(-x^2-3x-10)+(2-7x-6x^2)
=5x^2+4x-11+x^2+3x+10+2-7x-6x^2
=(5x^2+x^2-6x^2)+(4x+3x-7x)+(-11+10+2)
=0+0+1=1
so,无论x为何值时,原始都永恒不变.