Tim has $315 in five and tend dollar bills, the number of tens is 21 less than 7 times the number of fives.How many five dollar bills does he have?? WHAT ARE THE STEPS?
-
Write initial equation:
315 = 10x + 5y
Put the # of tens into equation: "the number of tens is 21 less than 7 times the number of fives"
10x = (5y)7 - 21
Plug in:
315 = ((5y)7 - 21) + 5y
Now that you have the equations, you can solve for y. Check it and make sure it works.
315 = 10x + 5y
Put the # of tens into equation: "the number of tens is 21 less than 7 times the number of fives"
10x = (5y)7 - 21
Plug in:
315 = ((5y)7 - 21) + 5y
Now that you have the equations, you can solve for y. Check it and make sure it works.