Sharon has some one dollar bills and som five dollar bills . She has 14 bills . The value of the bills are $30. Solve a system of equations using elimination to find how many of each kind of bill she has

Let the no. of one dollar bills be x and the no. of five dollar bills be y. She has 14 bills = > 1st equation => x+y=14 The value of the bills are $30 = > 2st equation =>  ($1)x + ($5)y = 30 Simultaneous equations :  x + y = 14 => x = 14 - y x + 5y = 30  Sub x = 14 - y into x + 5y = 30 , ie. (14 - y) + 5y = 30   =>  14 +4y = 30  => 4y = 16  => y=4

lets x = # of one dollar bills, y = # of five dollars bills x + y = 14 so x  = 14-y x + 5y = 30 substitute x  = 14-y into x + 5y = 30 x + 5y = 30 14 -y + 5y = 30 4y = 16   y = 4 x = 14 - y = 14-4=10 # of one dollars bills = 10 ($1x10 = $10) # of five dollars bills = 4    ($5 x 4 = 20) double check $10+$20 = $30 (The value of the bills are $30) 4+10=14 (She has 14 bills )