初一化简求值:已知:2x-3=0,求代数式(1+x)(1-x)+(x+2)²-(x+1)(2x-3)的值
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初一化简求值:已知:2x-3=0,求代数式(1+x)(1-x)+(x+2)²-(x+1)(2x-3)的值
初一化简求值:已知:2x-3=0,求代数式(1+x)(1-x)+(x+2)²-(x+1)(2x-3)的值
初一化简求值:已知:2x-3=0,求代数式(1+x)(1-x)+(x+2)²-(x+1)(2x-3)的值
(1+x)(1-x)+(x+2)²-(x+1)(2x-3)
=1-x²+x²+4x+4-(2x²-x-3)
=1-x²+x²+4x+4-2x²+x+3
=-2x²+5x+8
=-2x*x+5x+8
=-3x+5x+8
=2x+8
=3+8
=11
原式=1-x2+x2+4x+4 因为2x-3=0,所以(x+1)(2x-3)=0
=4x+5
=2*(2x-3)+9
=11
因为2x-3=0,则有
(1+x)(1-x)+(x+2)²-(x+1)(2x-3)
=(1+x)(1-x)+(x+2)²
=1-x²+x²+4x+4
=4x+5
=(2x-3)+(2x-3)+5+6
=0+0+11
=11