化简并求值:已知代数式2x²-1/2[6-2(x²-2)],其中x=-2

问题描述:

化简并求值:已知代数式2x²-1/2[6-2(x²-2)],其中x=-2

2x²-1/2[6-2(x²-2)]
=2x²-1/2(6-2x²+4)
=2x²-3+x²-2
=3x²-5
=3x4-5
=12-5
=7
不懂的欢迎追问.