Question

Emily has some $5 bills and $10 bills she has 15 bills she has $120 how many $5 bills does she have​

Answer 1

Step-by-step explanation:

Let F = The number of $5 bills and T = the number of $10 bills.  She has 15 bills total, so:

 

F+T = 15                

T = 15-F

 

She has $120 total:

 

$120 = ($5)*F + ($10)*T

$120 = $5*F + ($10)*(15-F)         [Substitute 15-F in place of T]

120 = 5F + 150 - 10F

-30 = -5F

 

6 = F

 

Check:

T= 15-F = 15=6 = 9

 

$120 = ($5)*6 + ($10)*9

$120 = $30 + $90

$120 = $120