化简求值:2x²-y²+(2x²-x²)-(2x²+3y²),其中a=-2,b=3
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化简求值:2x²-y²+(2x²-x²)-(2x²+3y²),其中a=-2,b=3
化简求值:2x²-y²+(2x²-x²)-(2x²+3y²),其中a=-2,b=3
化简求值:2x²-y²+(2x²-x²)-(2x²+3y²),其中a=-2,b=3
2x²-y²+(2x²-x²)-(2x²+3y²)
=2x²-y²+2x²-x²-2x²-3y²
=x²-4y²
当x=-2,b=3时,原式=(-2)²-4*3²=4-36=-32
如果题目没写错的话,化简后,应为x²-4y²。代入求值为(-2)²-4×3²=4-36=-32