Question

Ms. Lynch has 21 coins in nickels and dimes.

Answer 1

Answer:

Step-by-step explanation:So we know x + y = 21 and 5x +10y = 165 We line them up in columns    x +   y =   21  5x +10y = 165 To eliminate the x variable, I'll multiply every element in the 1st equation by -5. -5x + -5y = -105  5x + 10y =  165 Now we combine (add) the equations, which eliminates x altogether.  5y = 60   ...   y = 12 From there, x + 12 = 21  ...  x = 21-12  ...  x = 9 You should double check.  Do 9 nickles and 12 dimes equal $1.65? A very important thing to remember using this method is to do the same thing to each element in the equation that you change! I hope that helps.