Which of these is an example of proper formal writing for a business email?

Abusiness cycle reflects in economic activity, particularly real gdp. the stages of a business cycle

Kyle and alyssa paid $1,000 and $4,000 in qualifying expenses for their two daughters jane and jill, respectively, to attend the university of california. jane is a sophomore and jill is a freshman. kyle and alyssa's agi is $135,000 and they file a joint return. what is their allowable american opportunity tax credit after the credit phase-out based on agi is taken into account?

Acompany manufactures x units of product a and y units of product b, on two machines, i and ii. it has been determined that the company will realize a profit of $3 on each unit of product a and $4 on each unit of product b. to manufacture a unit of product a requires 7 min on machine i and 5 min on machine ii. to manufacture a unit of product b requires 8 min on mchine i and 5 min on machine ii. there are 175 min available on machine i and 125 min available on machine ii in each work shift. how many units of a product should be produced in each shift to maximize the company's profit p?