What would happen to GDP if a significant number of house-spouses who were previously staying home to care for their children began taking jobs and placing their children in day-care? Would the nation's well-being necessarily be better off?

The GDP will increase.

Explanation:

The number of women taking a job will result in the rise of real GDP because their participation will increase the number of economic activities. Therefore, a rise in economic activities will boost the GDP. But it would be uncertain to say that the well being of the nation will be better off because daycare will harm the bond of children and parents. Moreover, lack of parental supervision will result in the low performance of children at the latter age and if the child is at the age in which breastfeeding is required then lack of breastfeeding may harm child's physical and mental health as well.

the first successful, urban blues recording, selling more than 75,000 copies, was made in year 1920.

mamie smith recorded the first commercially successful example of the urban blues,   with the recording of “crazy blues”."crazy blues" was recorded on august 10, 1920, in new york city. within a month of the release of “crazy blues” it had sold 75,000 copies.