Acashier’s drawer has some $5 bills, some $10 bills, and some $20 bills. there are 15 bills worth a total of $185. how many $5 bills, $10 bills, and $20 bills are there?

4 * $20 , 10* $10 and 1 * $5 bills.

Step-by-step explanation:

Let   x =  20, y = 10 and z = 5 be the number of dollar bills.

x + y + z = 15    Also

20x + 10y + 5z = 185    Multiply the first equation by 5:

5x + 5y + 5z = 75          Subtract:

15x + 5y = 110                 Divide through by 5:

3x + y = 22                     There has to be an odd number of $5 bills.

 Trial and error:

Let x = 4 then y = 10 then z = 1:

Substitute these into  the second equation:

20(4) + 10(10) + 5 = 80 + 100 + 5 = 185.

So the answer is  4 $20 , 10 $10 and 1 $5 bills.

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.

127

whether it's diameter, or radius, i believe if i remember correctly from school, every amount has to always add up to 180. so if you take 53, and starting adding, long story short, taking 127 and adding it to 53, gives you 180.