Answer:
84 5$ bills and 42 $10 bills
Step-by-step explanation:
The problem has two variables, let:
F=number of $5 bills
T=number of $10 bills
Translate:
"a total of 126 bills, made up of fives and tens" means
126 = F + T (the number of each)
"total value of the money is $800" means
5F + 10T = 800 [use $10 and $5 times the number of bills]
Now, solve for either T or F in the first equation and put that into the second equation:
T = 126 - F
5F + 10(126-F) = 800 [now, all expressed in terms of F so we can solve for F]
5F + 1260 -10F = 800 [distribute]
-5F = -460 [subtract 1260 from both sides]
F = 92 [divide both sides by -1]
Now, put that value into either of the equations to solve for T (the second equation looks easy):
T = 126 - F
T = 126 - 92
T = 34
Checking (very important):
Is 126 = 92 + 34 ?
126 = 126 ? yes
Is 5(92) + 10(34) = 800 ?
460 + 340 = 800 ?
800 = 800 ? yes
