Hannah has only nickels and dimes in her wallet. She has a total of $2.50 and a total of 30 coins how many nickels does she have using system of equations?

Our school doesn't follow system of equations, rather a divisive pattern system. From that:

30/2 = 15

15 (10) + 15 (5) = 1.50 +.75 = 2.25

2.25=/=2.50

20 (10) + 10 (5) = 2.00 +.50 = 2.50

2.50 = 2.50

She has 10 nickels.

So relatively ... divide by half and start the input/output from there, continuing to adjust to find the answer you're looking for.

I think the answer would be 12