集合A={x丨(x-1)(x+2)≤0},B={x丨x<0}则A∪BA(负无穷,0] B(-无穷,1] C[1,2] D[1,正无穷)

问题描述:

集合A={x丨(x-1)(x+2)≤0},B={x丨x<0}则A∪B
A(负无穷,0] B(-无穷,1] C[1,2] D[1,正无穷)