问题 填空题 填空:(1)当a______时,a-1有意义;(2)当x______时,2x+3有意义. 答案 (1)由题意得:a-1≥0,解得a≥1.(2)2x+3≥0,解得:x≥-32.故答案为:≥1,≥-32.