Answer: Indentured servants
Although it was quite an imperfect system, which was subject to diverse kinds of abuse, indentured servitude was one way by which some early settlers were admitted into America in a bid to address the problem of labor shortages.
Indentured servants (individual or family) would voluntarily offer to serve under a labor contract for a period of two to seven years, or even more, based on many factors in order to join a vessel heading to America since they cannot afford the funds to pay for the voyage.
9(7+2)
His neighbor is out of town for nine days and he gets paid for these things every day so you would put the nine outside of the parentheses. You put seven plus two inside the parentheses because he is paid the sum of these numbers every day his neighbor is gone.