Question 936201
let x be the no of $ 5 bills
let y be the no of $ 20 bills
The number of $5 bills he has is 3 more than 4 times the number of $20 bills
hence
        x= 4*y+3
but total is $175
 hence 175=  x*5 +y*20
       put x= 4y+3 in the above equation
         175  = (4y+3)*5+y*20
        175 = 4y*5+3*5+20y
          175 =20y+15+20y
      175 = 20y+20y+15
   175 = 40y+15
   subtract 15 on both sides
 175-15 =40y+15-15
  160 =40y
 divide with 40 on both sides
  {{{160/40 = 40y/40}}}
   {{{4 = y}}}
       so no of $20 bills(y)= 4
    no of $ 5 bills(x) = 4*4+3
                       =16+3
                        =19
Result: no of $ 5 bills  = 19 & no of $20 bills  = 4