Question

A bank teller has 47 $20 and $5 bills in her cash drawer. The value of the bills is $490. How many $20 bills are

Answer 1

Answer:

A bank teller has 47 $20 and $5 bills.

The value of the bills is $490.

Number of $20 bills --> x

Number of $5 bills --> y

x + y = 47 --> x = 47-y

20x + 5y = 490 --> 20x = 490-5y

so

20(47-y) = 490 -5y

940-20y = 490-5y

940-490 = -5y+20y

15y = 450

y= 30

so

x = 47-30

x = 17

IN TOTAL --> 17 $20 bills and 30 $5 bills.

Answer 2

Answer:

x = 17 $20 bills

y = 30 $5 bills

General Formulas and Concepts:

• Order of Operations: BPEMDAS
• Multivariable Systems

Step-by-step explanation:

Step 1: Define variables

x = # of $20 bills

y = # of $5 bills

Step 2: Set up systems of equations

$\left \{ {{x+y=47} \atop {20x+5y=490}} \right.$

Step 3: Solve for x

1. Rewrite:                                        $\left \{ {{y=47-x} \atop {20x+5y=490}} \right.$
2. Substitute:                                     $20x+5(47-x)=490$
3. Distribute 5:                                   $20x+235-5x=490$
4. Combine like terms:                     $15x+235=490$
5. Subtract 235 on both sides:        $15x=255$
6. Divide both sides by 15:               $x=17$

By solving for x, we now know that we have 17 $20 bills.

Step 4: Solve for y

1. Define:                                        x + y = 47
2. Substitute:                                  17 + y = 47
3. Subtract 17 on both sides:         y = 30

Now we know that we have 30 $5 bills.