初一数学题

a-(2b-3c+4d)=-2b-( )2x^2-{-3x+5[4x^2-(3x^2-x-1)]-3}-5,其中x=-1.5,求式子值
2025-06-22 16:38:15
推荐回答(2个)
回答1:

-a-3c+4d
2x^2-{-3x+5[4x^2-(3x^2-x-1)]-3}-5
=2x^2-{-3x+5[x^2+x+1]-3}-5
=2x^2-{5x^2+2x+2}-5
=-3x^2-2x-7
=-3*(-1.5)^2-2*(-1.5)-7
=-3*2.25+3-7
=-10.75

回答2:

a-(2b-3c+4d)=-2b-(a+3c-4d )