Anthony has 7 bills. All the bills are tens or twenties. The bills Anthony has total $100 in value. How many of each hill does Anthony have?

Pretty sure the solving method is solving systems of equations but you have to isolate the variables and stuff.. please help!!

1 answer

Let X = tens and y = twenties

X = 7 - y

10 X + 20 y = 100

Substitute 7-y for X in the second equation and solve for y, then use first equation to find x.