先化简,后求值:(3x+5)(3x-5)-5x(x-1)-(2x-1)∧2,其中x=负9分之一

2025-06-27 22:54:46
推荐回答(4个)
回答1:

解答:
(3x+5)(3x-5)-5x(x-1)-(2x-1)∧2
=9x²-25-5x²+5x-(4x²-4x+1)
=9x²-25-5x²+5x-4x²+4x-1
=9x-26
代入x=-1/9
原式=9*(-1/9)-26=-1-26=-27

回答2:

(3x+5)(3x-5)-5x(x-1)-(2x-1)∧2,
=9x²-25-5x²+5x-4x²+4x-1
=9x-26
当x=-1/9时
原式=-1-26
=-27

回答3:

(3x+5)(3x-5)-5x(x-1)-(2x-1)∧2=9x^2-25-5x^2+5x-4x^2+4x-1
=9x-26
=-1-26
=-27

回答4:

解:原式=9(x)∧2-25-5(x)∧2+5x-4(x)∧2+4x-1=9x-26=-27