Solve for x: 7+4x=16+x

Given the choice between receiving $1.000.000 in one month or a single penny-doubled everyday for the period of one month; which option would you choice? show your work to support your answer. (assume that 1 month=30 days)

Which geometric principle is used to justify the construction below?

Will give a: 122 b: 90 c: 48 d: 180