-1/2a-2(a-1/2b²)-(3/2a-1/3b²)其中a=-2,b=2/3 先化简,在求值
问题描述:
-1/2a-2(a-1/2b²)-(3/2a-1/3b²)其中a=-2,b=2/3 先化简,在求值
答
-1/2a-2(a-1/2b²)-(3/2a-1/3b²)
=-1/2a-2a+b²-3/2a+1/3b²
=-4a+4/3b^2
=-4×(-2)+4/3×(2/3)^2
=8+16/27
=8又16/27