作业帮计算题和先化简,在求值,计算题 丨1-√2丨+√8-sin30°-6/√2+(π-3.14)^0先化简,在求值(x-1-8/x+1)÷x^2+2x-3/1-x^2,其中x=-2
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/04 09:41:09
计算题和先化简,在求值,计算题 丨1-√2丨+√8-sin30°-6/√2+(π-3.14)^0先化简,在求值(x-1-8/x+1)÷x^2+2x-3/1-x^2,其中x=-2
计算题和先化简,在求值,
计算题 丨1-√2丨+√8-sin30°-6/√2+(π-3.14)^0
先化简,在求值(x-1-8/x+1)÷x^2+2x-3/1-x^2,其中x=-2
计算题和先化简,在求值,计算题 丨1-√2丨+√8-sin30°-6/√2+(π-3.14)^0先化简,在求值(x-1-8/x+1)÷x^2+2x-3/1-x^2,其中x=-2
解
原式
=√2-1+2√2-1/2-3√2+1
=(√2+2√2-3√2)+(-1-1/2+1)
=-1/2
[(x-1)-8/(x+1)]÷[(x²+2x-3)/(1-x²)]
=[(x²-1)/(x+1)-8/(x+1)]×(1-x)(1+x)/(x+3)(x-1)
=(x²-1-8)/(x+1)×[-(x+1)/(x+3)]
=-(x-3)(x+3)/(x+1)×(x+1)/(x+3)
=-(x-3)
=-(2-3)
=1
丨1-√2丨+√8-sin30°-6/√2+(π-3.14)^0
=√2-1+√8-1/2-6/√2+1
=√2-1+2√2-1/2-3√2+1
=-1/2