15. n - 6 = 21......add 6 to both sides
n = 21 + 6
n = 27
16. p + 1 3/4 = 4 5/8...turn mixed numbers to improper fractions
p + 7/4 = 37/8....there is 2 ways to continue from here...I will show u both
(1) p + 7/4 = 37/8....multiply everything by common denominator of 8, this gets rid of the fractions.
8p + 14 = 37 (result of multiplying by 8)
8p = 37 - 14
8p = 23
p = 23/8
(2) p + 7/4 = 37/8...subtract 7/4 from both sides
p = 37/8 - 7/4...common denominator is 8
p = 37/8 - 14/8
p = 23/8
either way u use, u will arrive at the same answer