Question 500170
pennies	x					
nickels (	2	x	-5	)
dimes	(	3	x	-21	)

x+2x-5+3x-21=160

6x-26=160
+26
6x=160+26
6x=186
/6
x=31
pennies = 31
nickels ==> 2x-5 =>2*31-5=57
Dimes==>3x-21==>3*31-21=72

CHECK
31+57+72=160