Problema Solution

a cashier has $730 in twentyu-dollar bills and five dollar bills in all the cashier has 68 bills how manny twenty dolar bills does he have

Answer provided by our tutors

let x be number of twenty-dollar bills, y -- number of five dollar bills. Total number of them is 68, so we have: x+y=68


and total sum is 730, so we have 2nd equation: 730=20*x+5*y . We got system of equations with two equations:


730=20*x+5*y

x+y=68


y = 68-x


730=20*x+5*(68-x)

730=20*x+340-5*x

730-340=20*x-5*x

390=15*x

x=26

y=68-26=42