You have 52 coins consisting of dimes and nickels the coins total 3.55. how many coins are dimes how many are nickels

N = # of nickels 
d = # of dimes 

d + n = 52 so d = 52 - n
0.10d + 0.05n = 3.55

substitute d = 52 - n into 0.10d + 0.05n = 3.55
0.10d + 0.05n = 3.55
0.10(52 - n) + 0.05n = 3.55
5.2 - 0.10n + 0.05n = 3.55
-0.05n = - 1.65
 n = 33 nickels 

d = 52 - 33
d = 19 dimes

There are 33 nickels and 19 dimes.

You would plot 83 on the 83 line and you would plot -113 on the -113 line.

Move the decimal behind it