Fred is x years old. his sister, mary, is 4 years older than fred.

a) write down an expression in terms of x for mary's age.

How was rockefeller able to build his monopoly across the oil industry? he found newer and cheaper ways to refine oil, increasing his profits. he confined his business to ohio so he could buy all the refineries there. he bought up oil refineries, cut costs, and reinvested his profits in other refineries. he began to sell kerosene as well as oil, expanding his market.

The enforcement clause of the fourteenth amendment states what congress had the authority to a. grant citizenship to people b. change the constitution c. enforce only the bill of rights d. make laws to apply the amendment

Consider the following invention from the american industrial era. cotton gin – a machine that removed seeds from short-staple cotton which option explains how this invention contributed to the role of the united states as an emerging world power? a. it was in high demand abroad, as many european nations had begun farming cotton. b. it led to the decline of slavery in the south, which enhanced america’s international reputation. c. it freed up many slaves to become factory workers in northern cities, which improved the economy. d. it increased production efficiency of a us cash crop that was in high demand in other nations.