Paulette has $140 in $5 and $10 bills. The number of $10 bills is one less than twice the number of $5 bills. How many of each does she have?

Provide your answer below

?=$ 10 bills?=$5 bills

this needs a system

140=5x+10y

y = 2x-1

Now subsitute 2x-1 in for y

140=5x + 10 (2x-1)

140 = 25x - 10

bring over the 10

150 = 25x

the divide

x = 6

now substitue x in in 2x-1

2 (6) - 1 = 11

there you have it, you have 6 five dollar bills and 11 ten dollar bills.