I believe the answer is 19.1 and then you round it from there. Because 173 is not an even number. Check with someone else though. Hope this helps!
Answer:
11 dimes, 17 nickels
Step-by-step explanation:
d + n = 28, put one variable by itself on a side, d = 28 - n
.10d + .05n = 1.95
Sub the first equation into the second
.10(28 - n) + .05n = 1.95
2.8 - .10n + .05n = 1.95
2.8 - .05n = 1.95
-.05n = -0.85
n = 17 nickels
d + 17 = 28
d = 11 11 dimes
28.26 feet squared if using 3.14 for pi