①(-5/8)×(-4)⒉-0.25*(-5)*(-4)⒊ ②3x⒉+4x⒉-2x-2（x+2x-1）-x+1其中x=-2 ③2x⒉-5x+x⒉+4x其中x=-3

①(-5/8)×(-4)⒉-0.25*(-5)*(-4)⒊ ②3x⒉+4x⒉-2x-2（x+2x-1）-x+1其中x=-2 ③2x⒉-5x+x⒉+4x其中x=-3
①(-5/8)×(-4)⒉-0.25*(-5)*(-4)⒊ ②3x⒉+4x⒉-2x-2（x+2x-1）-x+1其中x=-2 ③2x⒉-5x+x⒉+4x其中x=-3

①(-5/8)×(-4)⒉-0.25*(-5)*(-4)⒊ ②3x⒉+4x⒉-2x-2（x+2x-1）-x+1其中x=-2 ③2x⒉-5x+x⒉+4x其中x=-3
①(-5/8)×(-4)⒉-0.25*(-5)*(-4)⒊
=(-5/8)×16-0.25×(-4)×(-5)×(-4)²
=-5×2+1×(-5)×16
=-10-80
=-90
②3x²+4x²-2x-2（x+2x-1）-x+1其中x=-2
=7x²-2x-2(3x-1)-x+1
=7x²-2x-6x+2-x+1
=7x²-9x+3
=7×4-9×2+3
=21
③2x⒉-5x+x⒉+4x其中x=-3
=3x²-x
=3×(-3)²-3×(-3)
=27+9
=36
⒉是平方吗