# How would you solve the following using a table? Andrew cashes a $180 check and wants the money in$10 and $20 bills. The bank teller gives him 12 bills. How many of each kind of bill does he receive? ##### 1 Answer Nov 26, 2014 We can solve this problem using a table and a pair of linear equations. (The dollar sign has been disregarded.) Now, we know that he has received a total amount of$180. Thus, our first equation is:

$10 x + 20 y = 180$ --------(1)

Now, we need another equation. We know that he has received 12 bills in total. Therefore, our second equation is:

$x + y = 12$

To make at least one variable term exactly like in the first equation, I will multiply this equation by 10, getting:

$10 x + 10 y = 120$ --------(2)

Subtracting equation (2) from (1),

$\left(+\right) 10 x + 20 y = 180$
$\left(-\right) 10 x + 10 y = 120$
$- - - - - - - - -$
$\left(=\right) 0 + 10 y = 60$

Therefore, $y = \frac{60}{10}$

$y = 6$

Substituting $y = 6$ in (2),

$10 x + 10 \left(6\right) = 120$
$10 x + 60 = 120$
$10 x = 120 - 60$
$10 x = 60$

$x = \frac{60}{10}$

$x = 6$

Thus, we can conclude that he receives 6 bills each of $10 and$20.