can youcheck these

write a 2 step equation:
half a dollar minus five dollars equals fifteen dollars:
n/2 -5 = 15

five hours more than one half of an hour equals fifteen hours:
n/2 + 5 = 15

two less than three times the number of feet of fencing required equals twelve feet: 3n -2 = 12

eight less than the quotient of daves gold score and 4 equals negative five
i got: s/4 -8 = -5

three times gails age increased by 2 years equals twelve years
i got: 3n +2 = 12

eight fewer than 4 times the elevation of a city equals negative five
4e - 8 = -5

can you check these? thank you