化简,(2x-1)²-(3x+1)(3x-1)+5x(x-1)),当x=0.5时,求原代数式的值
问题描述:
化简,(2x-1)²-(3x+1)(3x-1)+5x(x-1)),当x=0.5时,求原代数式的值
答
(2x-1)²-(3x+1)(3x-1)+5x(x-1))
=4x^2-4x+1-9x^2+1+5x^2-5x
=-9x+2 x=0.5
=-9x0.5+2
=-2.5